IUC Subjective Incidence: Annulment of Vehicle Circulation Tax Assessments 2008-2013

ARBITRAL DECISION

I. - REPORT

A - PARTIES

A..., with tax identification number..., hereinafter referred to as the "Claimant", filed a request for the constitution of an arbitral tribunal, under the terms of article 2(1)(a) and articles 10 et seq. of Decree-Law No. 10/2011, of 20 January (Legal Regime for Arbitration in Tax Matters, hereinafter referred to as "RJAT"), in order to examine the following claim against the Tax and Customs Authority (which succeeded, among others, the General Directorate of Taxes), hereinafter referred to as the "Respondent" or "AT".

B - REQUEST

1 - The request for constitution of the arbitral tribunal was accepted by the Honourable President of CAAD on 8 June 2015 and notified to AT on 15 June 2015.

2 - The Claimant did not appoint an arbitrator, therefore, under the terms of article 6(1) of RJAT, the undersigned was designated on 28-07-2015 by the Deontological Council of the Administrative Arbitration Centre as arbitrator of a Single Arbitral Tribunal, having accepted under the terms legally provided.

3 - The Parties were, on 28-07-2015, duly notified of this designation and did not express any will to refuse it, in accordance with the combined terms of articles 11(1)(a) and (b) and articles 6 and 7 of the Deontological Code.

4 - Under these circumstances, in accordance with article 11(1)(c) of Decree-Law No. 10/2011, of 20 January, as amended by article 228 of Law No. 66-B/2012, of 31 December, the arbitral tribunal was regularly constituted on 25-08-2015.

5 - On 26 January 2016, the Arbitral Tribunal, under article 16(c) of RJAT, issued an order dispensing with the meeting provided for in article 18 of the same statute, taking into account both the fact that the subject matter of the dispute concerns fundamentally a matter of law and the understanding established between the parties to that effect, the same having not requested any autonomous evidence procedures, with the pertinent documents being included in the proceedings and the administrative process being attached to the case.

6 - The present Claimant requests that this Arbitral Tribunal:

a) - Declare the annulment of the tax assessment acts relating to the Single Circulation Tax (hereinafter referred to as IUC), referenced in the case file, relating to the years 2008 to 2013, with respect to the vehicle with registration number ...-..-...

b) - Declare the annulment of the acts applying penalties for untimely payment of IUC related to the aforementioned assessments.

c) - Order the annulment of the tax enforcement proceedings that were instituted for collection of the IUC debt referenced in the proceedings.

d) - Condemn the Tax and Customs Authority to repay the amount of € 1,391.80, unduly paid, plus the costs and expenses incurred with the enforcement proceedings for coercive collection of the tax, as well as to the payment of compensatory interest (hereinafter referred to as JC), which are associated therewith.

e) - Condemn the Tax and Customs Authority to repay the amount relating to the costs and expenses incurred with the enforcement proceedings for coercive collection of the tax.

C - GROUNDS FOR THE CLAIM

7 - The Claimant, in the substantiation of its request for arbitral decision, affirms, in summary, the following:

8 - That on diverse occasions it went to the Finance Service of Cascais -..., in order to verbally and documentally expose the facts that sustain the illegality of the assessments that were notified to it.

9 - That it resorted to legal support, having, under those circumstances, filed a request on 03-07-2014 at the Finance Service of Cascais - ..., in which, in writing, it detailed all the expositions that it had verbally made at the mentioned Finance Service.

10 - That the aforementioned Finance Service responded to the request of 03-07-2014, maintaining both the assessments made and the penalties applied, without presenting any grounds that would respond to the arguments that had been presented to it.

11 - That it filed a Request for Review of Tax Acts relating to IUC assessments for the years 2008 to 2013, concerning the vehicle with registration number ...-..-..., which was denied, and of which it was notified by official letter No. ..., of 10-04-2015 of the Finance Service of Cascais - ...

12 - That the aforementioned Request for Review, after prior hearing, was denied by order issued on 10-04-2015 by the chief of the Finance Service of Cascais - ..., in a replacement capacity, of which it was notified by official letter No. ..., of 10-04-2015 of the aforementioned Finance Service.

13 - That it was the owner of a vehicle of the Volvo brand, with registration number ...-..-..., which, following an accident occurring on 17-10-2005, became completely unusable, with the insurance company B..., SA considering the infeasibility of its repair and inclined toward the total loss of the vehicle.

14 - That it presented with the Finance Services of Cascais - ... proof documents of the sale of the vehicle as scrap, following an accident that resulted in its total loss.

15 - That the vehicle in question was, on 13-01-2006, sold as scrap for the amount of € 200.00 to the firm C..., with headquarters in ...- ...- Feira, which is evidenced by the receipt of 13-01-2006, attached to the case file, with the vehicle in question thereafter becoming the property of the aforementioned purchaser, despite the Claimant continuing as its owner in the Motor Vehicle Registry Office.

16 - That, as proof of the sale of the vehicle in question, it attached both the letter from the insurance company B..., SA and the receipt relating to the sale of the vehicle with registration number ...-..-...

17 - That the amounts it paid, both relating to the IUC assessments for the years 2008 to 2013 and relating to the penalties associated with the untimely payment of the aforementioned tax, total the sum of € 1,391.80.

18 - That the IUC assessments made by the Tax Administration are due solely to the fact that in the motor vehicle registry it appears as the owner of the vehicle with registration number ...-..-...

19 - That the motor vehicle registry does not have a constitutive nature, functioning only as a mere presumption of the right of ownership of the vehicles, which is rebuttable by proof of the sale of the vehicle.

20 - That article 3(1) of CIUC establishes a legal presumption, which in light of article 73 of LGT always admits contrary proof, which is extensively supported in the decisions of Tax Arbitration.

D - RESPONSE OF THE RESPONDENT

21 - The Respondent, the Tax and Customs Authority (hereinafter referred to as AT), presented its Response on 29-09-2015.

22 - In the aforementioned Response, AT understands that the factual and legal grounds invoked by the Claimant cannot succeed, because and firstly,

23 - The tax legislator, by determining in article 3(1) of CIUC who are the passive subjects of IUC, expressly and intentionally established that such subjects are the owners, being considered as such the persons in whose names the same are registered.

24 - It emphasizes that the legislator did not use the expression "it is presumed" as it could have done, for example, in the following terms: "the passive subjects of the tax are the owners of the vehicles, and are presumed as such the natural or legal persons, of public or private law, in whose names the same are registered". (See article 11 of the Response)

25 - It considers that the understanding that the legislator established a presumption in article 3 of CIUC, as the Claimant understands, would unequivocally be making an interpretation contra legem. (See article 18 of the Response)

26 - It understands that given the wording of article 3(1) of CIUC it is not manifestly possible to invoke that it is a presumption, being rather a clear option of legislative policy adopted by the legislator, whose intention, within its freedom of legislative formation, was that for purposes of IUC owners should be those who, as such, appear in the registry.

27 - It refers that the aforementioned understanding has already been adopted by the jurisprudence of our courts, transcribing for this purpose part of the judgment of the Administrative and Tax Court of Penafiel, issued in Case No. 210/13.OBEPNF. (See articles 19 and 20 of the Response)

28 - Referring to the systematic element of interpretation, AT considers that the solution advocated by the Claimant is intolerable, to the extent that it has no legal support, neither in article 3(1) of CIUC nor in other norms established in the aforementioned Code.

29 - It considers equally that in light of a teleological interpretation of the regime established throughout the IUC Code, the interpretation advocated by the Claimant, in the sense that the passive subject of IUC is the effective owner regardless of not appearing in the motor vehicle registry, is manifestly wrong, to the extent that it is the very ratio of the regime established in CIUC that constitutes clear proof that what the tax legislator intended was to create a tax based on the taxation of the owner of the vehicle, as recorded in the motor vehicle registry. (See article 39 of the Response)

30 - It adds that CIUC carried out a reform of the regime for taxation of vehicles in Portugal, substantially altering the automobile taxation regime, with the passive subjects of the tax becoming the owners recorded in the property registry, regardless of the circulation of vehicles on public roads. (See article 44 of the Response)

31 - It also considers that the interpretation put forward by the Claimant is incompatible with the Constitution, to the extent that such interpretation translates into the violation of the principle of trust, the principle of legal certainty, the principle of efficiency of the tax system and the principle of proportionality. (See articles 50 and 52 of the Response)

32 - It adds that the documents attached by the Claimant (copies of letter and official letter from the Insurer and receipt) do not constitute sufficient proof to "undermine the (supposed) legal presumption established in article 3 of CIUC", to the extent that, in particular, the document/receipt is not apt to prove the celebration of a synallagmatic contract, such as a purchase and sale. (See articles 63, 64, 65 and 72 of the Response)

33 - It further states that it was not the Respondent who gave rise to the filing of the request for arbitral decision, but rather the Claimant, and should consequently be the Claimant be condemned to the arbitral costs "under the terms of article 527(1) of the New Code of Civil Procedure ex vi of article 29(1)(e) of RJAT", also referring to the fact that the legal prerequisites conferring the right to compensatory interest are not met.

34 - It considers, finally, that, given all the arguments set forth, the request for arbitral decision should be judged unsubstantiated, with the tax assessment acts challenged remaining in the legal order, with the Respondent being absolved of the request, also referring that the tribunal should consider itself incompetent to assess the legality of the penalties.

E - ISSUES TO BE DECIDED

35 - It is therefore necessary to examine and decide.

36 - Given the foregoing, regarding the positions of the Parties and the arguments presented, the main issues to be decided are whether:

a) - The Arbitral Tribunal is materially competent to examine the request for annulment of the penalties, with the consequent repayment of the corresponding amounts paid by the Claimant.

b) - The tribunal is materially competent to examine the request for annulment of the enforcement proceedings, with the repayment of the amounts relating to the costs and expenses incurred by the Claimant with the aforementioned enforcement proceedings.

c) - Whether the norm of subjective incidence contained in article 3(1) of CIUC establishes or not a presumption.

d) - What is the legal value of the motor vehicle registry in the economy of CIUC, particularly for purposes of the subjective incidence of this tax.

e) If, on the date of the occurrence of the taxable event, the vehicle has already been previously alienated, although the right of ownership of it continues to be registered in the name of its former owner, for purposes of article 3(1) of CIUC, the passive subject of IUC is the former owner or the new owner.

F - PROCEDURAL REQUIREMENTS

37 - The Arbitral Tribunal is regularly constituted and materially competent, under the terms of article 2(1)(a) of Decree-Law No. 10/2011, of 20 January.

38 - The Parties enjoy legal personality and capacity, are legitimate and are legally represented (see article 4 and article 10(2) of Decree-Law No. 10/2011 and article 1 of Ordinance No. 112/2011, of 22 March).

39 - The proceedings are not affected by defects that would invalidate them.

40 - Taking into account both the administrative tax proceedings and the documentary evidence attached to the case, it is now necessary to present the factual matter relevant to understanding the decision, as it is set out in the terms mentioned below, but it is important, first of all, to address the tribunal's competence regarding the request for annulment of the penalties and repayment of the amounts paid for this purpose, as well as the request for annulment of the enforcement proceedings.

G - ANNULMENT OF PENALTIES AND ENFORCEMENT PROCEEDINGS

41 - Taking into account, on one hand, the provisions of articles 97, 577, 578 and 608 of CPC and considering, on the other hand, the provision of article 13 of the Code of Procedure in Administrative Courts (CPTA), applicable here under article 29(1)(c) of RJAT, it is necessary to first address the issue relating to both the request for repayment of the amounts paid for penalties and the request for annulment of the enforcement proceedings, to the extent that it raises the question of whether the arbitral tribunal has competence for that purpose, whose examination precedes that of any other matter.

42 - The Claimant, in its request for arbitral decision, in addition to requesting the annulment of the official tax assessments of IUC, as identified in the proceedings, relating to the years 2008, 2009, 2010, 2011, 2012 and 2013, concerning the vehicle with registration number ...-..-... identified in the case file, also requested the annulment of the penalties that were applied to it, as well as the annulment of the enforcement proceedings.

REGARDING PENALTIES

43 - Penalties, as sanctions of an administrative nature, do not fall, from the outset, within tax legal relationships, with the amounts associated with them not being confusable with taxes.

44 - It is known that the tax legal relationship, as notably results from articles 1(2) and (3) of LGT and article 30 of that same statute, implies, in addition to the active and passive subjects of that relationship, that its object concerns the assessment and collection of taxes or the resolution of conflicts arising from them.

45 - The scope of the competence of tax arbitral tribunals comprises precisely the claims that fall within the aforementioned tax legal relationship. Article 2(1) of RJAT establishes, in the wording given to it by Law No. 64-B/2011, of 30 December, that the competence of the aforementioned tribunals comprises: a) The declaration of illegality of acts of tax assessment, self-assessment, withholding at the source and payment on account; b) The declaration of illegality of acts of determination of taxable matter and acts of fixing patrimonial values, which demonstrates the absence of powers of tax tribunals for purposes of examining decisions regarding the application of penalties, within the framework of offences associated with untimely payment of taxes due.

46 - What the law clearly privileged, regarding the competences of arbitral tribunals in tax matters, was the judgment of cases that in administrative and tax courts take the procedural form of judicial review, in accordance with article 101(a) of LGT and article 97(1)(a-f) of CPPT, it should be noted that, even in this domain, there are limitations, as results, in particular, from article 2 of Ordinance No. 112-A/2011, of 22 March.

47 - In this regard, Jorge Lopes de Sousa refers, in Commentary on the Legal Regime for Tax Arbitration, integrated in the Guide to Tax Arbitration, Almedina, March 2013, p. 105, that "[…] thus, outside the competence of these arbitral tribunals are the examination of disputes generated […] in tax administrative offense proceedings".

48 - Thus, the request made by the Claimant for annulment of the penalties that were applied to it following the untimely payment of IUC does not fall within the framework of arbitrable claims, and this tribunal cannot examine them.

49 - Under these circumstances, this Arbitral Tribunal cannot examine, ratione materiae, the alleged illegality of the decisions relating to the application of the penalties in question, nor consequently order the repayment of the amounts paid for this purpose.

REGARDING ENFORCEMENT PROCEEDINGS

50 - The Claimant, in accordance with documents in the case file, identifies the tax enforcement proceedings that were instituted against it as a consequence of non-payment of IUC relating to the tax assessment acts, relating to the vehicle with registration number ...-..-..., for the years 2008 to 2013, requesting their annulment.

51 - The arbitral tribunals, as already mentioned above, have at the core of their competences the judgment of cases that in administrative and tax courts take the procedural form of judicial review, not contemplating consequently the examination and decision of specific issues of tax enforcement proceedings that have been instituted.

52 - In this sense, it is again appropriate to refer to Jorge Lopes de Sousa, idem, when he tells us that "[…] thus, outside the competence of these arbitral tribunals are the examination of disputes generated in tax enforcement proceedings […]".

53 - Under these circumstances, this Arbitral Tribunal cannot examine, by reason of matter, the requested annulment of the enforcement proceedings, opportunely instituted for collection of the tax debt in question, nor consequently order the repayment of the amounts relating to the costs incurred with the aforementioned enforcement proceedings, which, moreover, are not at all identified in the proceedings.

II - LEGAL REASONING

G - FACTUAL REASONING

54 - Regarding relevant factual matters, this tribunal considers the following facts as established:

55 - The Claimant, A..., with tax identification number..., was notified of IUC assessments relating to the years 2008, 2009, 2010, 2011, 2012 and 2013, concerning the vehicle with registration number ...-..-..., identified in the case file.

56 - The Claimant went, on diverse occasions, to the Finance Service of Cascais - ..., in order to verbally and documentally expose the facts that sustain the illegality of the assessments that were notified to it.

57 - There was, on the part of the Claimant, recourse to legal support, having, under those circumstances, a request been filed on 03-07-2014 at the Finance Service of Cascais - ..., in which, in writing, are detailed all the expositions that had verbally been made at the aforementioned Finance Service.

58 - The aforementioned Finance Service responded to the request of 03-07-2014, maintaining both the assessments made and the penalties applied, without presenting any grounds that would respond to the arguments that had been presented to it.

59 - A Request for Review of Tax Acts was filed by the Claimant relating to IUC assessments, relating to the years 2008 to 2013, concerning the vehicle with registration number ...-..-..., which was denied, with such denial being notified by official letter No. ..., of 10-04-2015 of the Finance Service of Cascais - ...

60 - The aforementioned Request for Review, after prior hearing, was denied by order issued on 10-04-2015 by the chief of the Finance Service of Cascais - ..., in a replacement capacity, of which the Claimant was notified by official letter No. ..., of 10-04-2015 of the aforementioned Finance Service.

61 - The Claimant was the owner of a vehicle of the Volvo brand, with registration number ...-..-..., which, following an accident occurring on 17-10-2005, became completely unusable, with the insurance company B..., SA considering the infeasibility of its repair and inclined toward the total loss of the vehicle.

62 - The Claimant presented with the Finance Service of Cascais - ... proof documents of the sale of the vehicle as scrap, following the accident that resulted in its total loss.

63 - The vehicle in question was, on 13-01-2006, sold as scrap for the amount of € 200.00 to the firm C..., with headquarters in ...- ...- Feira, with the vehicle in question thereafter becoming the property of the aforementioned purchaser, despite the Claimant continuing as its owner in the Motor Vehicle Registry Office.

64 - The Claimant, as proof of the sale of the vehicle in question, attached both the letter from the insurance company B..., SA and the receipt relating to the sale of the vehicle with registration number ...-..-...

65 - The amounts that the Claimant alleges to have paid, namely relating both to IUC assessments for the years 2008 to 2013 and to penalties associated with the untimely payment of the aforementioned tax, total the sum of € 1,391.80.

REASONING REGARDING PROVEN FACTS

66 - The facts established are based on the documents mentioned, relating to each of them, to the extent that their adherence to reality was not questioned.

UNPROVEN FACTS

67 - The alleged payment of the sum of € 1,391.30 for tax and penalties is not proven.

H - LEGAL REASONING

68 - The factual matter is established, it now being necessary to proceed to its legal subsumption and determine the law applicable to the underlying facts, in accordance with the issues to be decided set out in paragraph 36.

69 - The decisive issue in the present proceedings, regarding which there are absolutely opposed understandings between the Claimant and AT, is whether the norm of subjective incidence contained in article 3(1) of CIUC establishes or not a rebuttable presumption.

70 - The positions of the parties are known. Indeed, for the Claimant, the provision of article 3(1) of CIUC establishes a legal presumption, which in light of article 73 of LGT always admits contrary proof.

71 - The Respondent, for its part, considers, in particular, that the interpretation defended by the Claimant regarding what is established in article 3(1) of CIUC is manifestly wrong, to the extent that it is the very ratio of the regime established in CIUC that constitutes clear proof that what the tax legislator intended was to create a tax based on the taxation of the owner of the vehicle, as recorded in the motor vehicle registry.

I - INTERPRETATION OF THE NORM OF SUBJECTIVE INCIDENCE CONTAINED IN ARTICLE 3(1) OF CIUC

72 - Regarding this issue, namely whether the norm of subjective incidence contained in article 3(1) of CIUC establishes a presumption, it should be noted that the established jurisprudence in CAAD points to the understanding that the said norm establishes a legal presumption. Indeed, from the first Decisions issued on this matter in the year 2013, among which may be mentioned in particular those issued in the framework of Cases Nos. 14/2013-T, 26/2013-T and 27/2013-T, to the more recent ones that can be indicated as the Decisions issued in Cases No. 69/2015-T and No. 79/2015-T, passing through numerous Decisions issued in the year 2014, of which are mentioned, merely by way of example, the Decisions issued in Cases Nos. 34/2014-T, 120/2014-T and 456/2014-T, all point to the understanding that article 3(1) of CIUC establishes a rebuttable legal presumption.

In this regard, should also be considered the understanding contained in the Judgment of the Central Administrative Court South, issued on 19-03-2015, Case 08300/14, available at: www.dgsi.pt, which supports the aforementioned jurisprudence, when it expressly states that article 3(1) of CIUC "[…] establishes a legal presumption that the holder of the motor vehicle registry is its owner, and such presumption is rebuttable by virtue of article 73 of LGT".

This is an understanding which we fully embrace and which is given, without further ado, as valid and applicable in the present case, not being considered, consequently, necessary other developments, given the abundant reasoning set forth in the aforementioned Decisions and in the aforementioned Judgment.

73 - Being this the understanding which, regarding article 3(1) of CIUC, is completely embraced by this tribunal, it is, however, still important to point out the lack of reason that, with all due respect, assists the Respondent when, in articles 52 and 54 of its response, it alleges that the interpretation that goes in the direction of understanding that a rebuttable legal presumption is established in article 3(1) of CIUC violates the constitutional principles of trust and legal certainty, of the efficiency of the tax system and of proportionality.

Let us examine, then, this issue.

Let us see,

- Regarding the principle of proportionality, it is first important to note that the same, to the extent that it is materially inherent to the regime of rights, freedoms and guarantees, being inscribed in their defense, aims, in essence, to govern the conduct of the Public Administration in order that its activity in its relationship with private parties be guided by the choice of the most adequately balanced measures for the pursuit of the public interest.

As Professor Freitas do Amaral teaches, in Course in Administrative Law, Vol II, Almedina, 2002, pp. 127/128 et seq., the "principle of proportionality constitutes a constitutive manifestation of the principle of the Rule of Law", with "[…] the idea being strongly anchored that, in a democratic Rule of Law state, the measures of public powers should not exceed what is strictly necessary for the realization of the public interest".

The principle of proportionality, adds the aforementioned Professor, ibidem, p. 129, means that "[…] the limitation of goods or private interests by acts of public powers must be adequate and necessary to the concrete ends pursued by such acts, as well as tolerable when confronted with those ends".

Regarding the principle of proportionality, it is also appropriate to note what J. J. Gomes Canotilho and Vital Moreira tell us, in CONSTITUTION OF THE PORTUGUESE REPUBLIC, ANNOTATED, VOLUME I, 4th Edition, 2007, Coimbra Editora, pp. 392/393, when they consider that the aforementioned principle is decomposable into three sub-principles, namely: "[…] a) principle of suitability (also designated as the principle of adequacy); b) principle of necessity (also called the principle of necessity or indispensability); c) principle of proportionality in the strict sense, which means that the restrictive legal means and the ends obtained must be situated in a "just measure", preventing the adoption of disproportionate, excessive legal restrictive measures in relation to the ends obtained […]".

The aforementioned sub-principles all have a common denominator, which is that of just balance and permanent coherence between the purposes of the law and the means adopted to achieve such purposes, which, in the circumstances and attempting the transposition of the said principle to the case at hand, will imply answering the question of what is the appropriate interpretation of article 3(1), with a view to achieving the legal purposes provided for in article 1 of CIUC, which translate into the imposition of a fiscal burden on the actual owners of motor vehicles (and not necessarily those in the registry) in the measure of the environmental and road cost that they cause.

As Professor J. J. Gomes Canotilho refers in Constitutional Law and Theory of the Constitution, Almedina - Coimbra, 1998, pp. 264 et seq., the most important field of application of the principle of proportionality or prohibition of excess, which has constitutional basis in articles 18(2) and 266(2) of the CRP, "[…] is that of the restriction of rights, freedoms and guarantees by acts of public powers. However, the logical domain of application of the principle of proportionality extends to conflicts of legal goods of any kind." The administration, adds the aforementioned author, idem, "[…] must always observe, in each concrete case, the requirements of the prohibition of excess […]".

In this same sense points the jurisprudence, in particular the judgment of the STA of 01-07-1997, Case No. 041177, available at: www.dgsi.pt, when it considers that the principle of proportionality in the broad sense comprises the congruence, adequacy or suitability of the means or measure to achieve the legally proposed end, and in the strict sense encompasses the prohibition of excess.

The principle of proportionality is a corollary of the principle of justice, which means and implies that in its conduct the Public Administration must harmonize the specific public interest that falls to it to pursue with the rights and legitimate interests of private parties potentially affected by its acts, interests and rights which, in the case at hand, reduce to the non-taxation in IUC of persons who are no longer owners of the vehicles and who consequently contribute in no way to the realization of any road and environmental cost.

What is important is to balance the legal purposes and the means to pursue them, and, within a weighing judgment, to identify the most adequate means for this effect, which in the case translates into the interpretation embraced by the arbitral tribunal.

It could even be said that the understanding that article 3(1) of CIUC establishes a rebuttable legal presumption corresponds to the only interpretation that coherently aligns with the said principle of equivalence, and which aligns with the principles of justice and proportionality.

The interpretation that understands that a rebuttable legal presumption is established in article 3(1) of CIUC is thus the only one that permits ensuring the pursuit of the purposes envisioned by the law - to burden the owners of motor vehicles in the measure of the environmental and road cost that they cause - as stated in article 1 of CIUC, which means that the passive subjects of IUC are, presumptively, the persons in whose names the vehicles are registered, that is, the aforementioned passive subjects are, in principle, and only in principle, the persons in whose names such vehicles are registered, there being thus no other interpretation capable of achieving the aforementioned legal purposes, only thus, reaffirms itself, are the aforementioned principles of proportionality and justice fulfilled.

The contrary understanding, namely that considered by AT, which interprets article 3(1) of CIUC as not establishing a rebuttable legal presumption, understanding that the passive subjects of IUC are definitively the persons in whose names the vehicles are registered, in the just measure in which it leads to the imposition of a fiscal burden on those who may no longer be the owner of the vehicle in question and who, in this way, do not pollute, distancing from fiscal subjection those who, in reality, are the effective causers of the environmental and road damages arising from the use of vehicles of which they are the real owners, makes evident that the legally prescribed purposes would not at all be achieved, not respecting thus the principle of equivalence which, within the framework of CIUC, has an absolutely structuring function. Such understanding, this one yes, does not show itself, in these circumstances, in harmony with the principle of proportionality.

The interpretation made by the tribunal in the decision which now reforms itself, took exactly into account the principle of proportionality when, against what the Respondent intended, it takes due account of the fact that the final registry does not produce constitutive effect for being intended to give publicity to the registered act, functioning only as a mere rebuttable presumption of the existence of the right and when, in homage to that principle, it attends to the principle of equivalence, as a fundamental element of CIUC.

- As for the efficiency of the tax system, it could be said that the efficiency of the Administration in general, or of AT in particular, in the current sense, would correspond to the capacity/work methodology oriented towards the optimization of the work executed or services rendered, which means to produce the maximum, in quantity and quality, with the minimum of costs and means, having nothing to do with the observance of legally established principles and with the respect for the rights of citizens, whether in the capacity of taxpayers or not.

In the technical sense, it could be said that the principle of efficiency of the tax system is commonly regarded in the domain of tax procedure as a corollary of the principle of proportionality, which as is known imposes an adequate proportion between the legal purposes and the means chosen to achieve these purposes, or, as referred by Diogo Leite Campos, Benjamim Silva Rodrigues and Jorge Lopes de Sousa, in General Tax Law, Annotated and Commented, 4th Edition 2012, Encontro de Escrita, Lda, Lisbon, p. 488, in the annotations to article 55 of LGT, it is a principle that obliges "[…] the tax administration to refrain from imposing on taxpayers obligations that are unnecessary to the satisfaction of the ends that it seeks to pursue".

In this framework, the aforementioned principle of efficiency of the tax system will mean the capacity to achieve the legally fixed objectives with the minimum of means, which will have nothing to do with the respect for the rights of citizens, nor with the need for observance of other principles to which the tax administration must subordinate its activity, in particular the inquisitorial principle and the discovery of material truth, and cannot obviously the application of the aforementioned principle of efficiency be made either with prejudice to the rights of citizens or by the failure to observe the legal purposes. [1]

- As for the principle of legal certainty and trust, it should be noted, first of all, that this latter principle, that of trust, is a concretization of the principle of good faith, which, having establishment in our legal order since 1996, came to have express constitutional inscription, as contained in article 266(2) of the CRP, where it is established that "The organs and agents of the Administration are subordinated to the Constitution and the law and must act, in the exercise of their functions, with respect for the principles of equality, proportionality, justice, impartiality and good faith". (underlining ours)

Regarding good faith, it is appropriate to note what Professor Freitas do Amaral refers when, in Course in Administrative Law, Vol. II, Almedina, 2002, pp. 135/136, citing Professor V. Fausto de Quadros, tells us that "[…] the Public Administration is obliged to obey bona fide in its relations with private parties. More: it should even give, also there, the example to private parties of the observance of good faith in all its manifestations as the essential nucleus of its ethical behavior. Without this, it can never be affirmed that the State (and with it other public entities) is a person of good will".

On the other hand, the principle of trust is also held to be a consequence of the principle of legal certainty, inseparable from the Rule of Law, which, having to guarantee a minimum of certainty in the rights of persons and in the legal expectations created for them, generates confidence of citizens in the legal protection of the Public Administration.

Regarding the principles of legal certainty and protection of trust, Professor J. J. Gomes Canotilho tells us in Constitutional Law and Theory of the Constitution, Almedina - Coimbra, 1998, p. 250 et seq., that the aforementioned principles are closely associated, being considered that "[…] legal certainty is connected with objective elements of the legal order - guarantee of legal stability, security of orientation and realization of law - while protection of trust is more connected with the subjective components of security, in particular the calculability and foreseeability of individuals in relation to the legal effects of acts of public powers". In any case, adds the aforementioned Professor, idem, that the "[…] general principle of legal certainty in the broad sense (thus encompassing the idea of protection of trust) can be formulated as follows: the individual has the right to be able to trust that to his or her acts or to public decisions affecting his or her rights, positions or legal relationships grounded in valid legal norms the legal effects provided and prescribed by those same norms are linked".

It follows from this doctrine that persons, upon alienating their vehicles, must be secure in the knowledge that, should they proceed to sell the vehicles of which they are owners and the same not being registered in the name of the acquirers, the legal effects resulting from this will be those provided for and arising from the legal norms in force and their adequate interpretation, in light of the legal purposes of those same norms, which in the present case led the arbitral tribunal to consider the registry as a rebuttable presumption of the existence of the right and that only persons who cause road and environmental costs should be taxed.

The best way to, in the case at hand, ensure legal certainty in the broad sense is thus that concretized via the interpretation made by the arbitral tribunal, when it considers that there is established in article 3(1) of CIUC a rebuttable legal presumption, allowing any citizen who proceeds to sell to a third party a motor vehicle the possibility of demonstrating that at the time IUC was exigible, he or she was no longer its owner nor responsible for the payment of that tax.

- In addition to what is set forth above, it will also be important to know whether the interpretation embraced by the arbitral tribunal, in addition to not conflicting with any of the aforementioned principles, is directly and substantively inscribed in the context of the constitutional order.

Regarding the interpretation of law in light of the Constitution, or interpretation in conformity with the Constitution, Professor Jorge Miranda tells us, in Manual of Constitutional Law, TOME II, Introduction to Constitutional Theory, 2nd edition, Coimbra Editora, 1987, p. 232 et seq., that what is at issue, first and foremost, is "[…] taking into account, within the systematic element of interpretation, what relates to the Constitution. Indeed, each legal provision must not only be grasped within the set of provisions of the same law and each law within the set of the legislative order; it must also be considered in the context of the constitutional order [..]". (underlining ours)

The understanding that considers that a rebuttable legal presumption is established in article 3(1) of CIUC supports itself on diverse elements of interpretation, among which it is appropriate to mention the systematic element, to the extent that interpretation in conformity with the Constitution implies that within the systematic element of interpretation the account is taken of what relates to the Constitution.

Regarding the aforementioned systematic element it is appropriate to refer to the following:

a) In the understanding of BAPTISTA MACHADO, in Introduction to Law and Legitimating Discourse, p. 183, the systematic element "[…] comprises the consideration of the other provisions that form the normative complex of the institute in which the norm to be interpreted is integrated, that is, that regulate the same matter (context of the law), as well as the consideration of legal provisions that regulate parallel normative problems or related institutes (parallel places). It also comprises the systematic place that befits the norm to be interpreted in the global legal order, as well as its consonance with the spirit or intrinsic unity of the entire legal order".

b) It is known that a legal principle, in the case the principle of equivalence, does not exist in isolation, but is instead linked by an intimate nexus with other principles that integrate, at the more global level, the respective legal order, in the case, with the other principles embodied in the system inscribed in CIUC, and with other constitutionally established principles. In that sense, each article of a given legal diploma, in the case CIUC, will only be understandable if we situate it both before the other articles that follow or precede it and before the constitutional order.

c) As regards the systematization of CIUC, concerns of an environmental order were determinative in order that the aforementioned principle of equivalence be from the outset inscribed in the first article of the aforementioned Code, which necessarily leads to the subsequent articles, to the extent that they are grounded in such principle, being influenced by it. This occurred, in particular, with the taxable base, which came to be constituted by diverse elements, particularly those relating to levels of pollution, and with the tax rates established in articles 9 to 15, which were influenced by the environmental component, and naturally also with the subjective incidence itself, provided for in article 3 of CIUC, which cannot escape the aforementioned influence.

d) The aforementioned principle of equivalence, as noted by Sérgio Vasques, in Special Consumption Taxes, Almedina, 2001, p. 122 et seq., implies that "[…] the tax must correspond to the benefit that the taxpayer obtains from the public activity; or to the cost that the taxpayer imputes to the collective by its own activity". Adds the aforementioned author, idem, that "Thus, a tax on automobiles based on a rule of equivalence will be equal only if those who cause the same road wear and the same environmental cost pay the same tax; and those who cause different wear and environmental cost pay different tax as well." For this reason, as also refers the quoted author, idem, the concretization of the principle of equivalence dictates special requirements "[…] regarding the subjective incidence of the tax [..]."

The aforementioned principle which informs the current Single Circulation Tax is inscribed in the environmental concerns established in article 66(2)(a) of the CRP and in the need - in order to ensure the right to environment within the framework of sustainable development - to "Prevent and control pollution and its effects and harmful forms of erosion", concerns which are manifestly considered in the interpretation defended by the arbitral tribunal.

On the other hand, the provision of article 66(2)(h) of the Constitution, when it establishes that within the framework of sustainable development it falls to the State to "ensure that fiscal policy is compatible with development and protection of environment and quality of life", entails as a corollary the principle of the polluter pays, which concretizes the idea inscribed therein that he who pollutes must, for that reason, pay, thus being the interpretation defended by the arbitral tribunal in perfect accordance with the constitutional order.

e) It is still appropriate to leave a brief note, merely to raise the question of why the rules contained in article 9 of the Civil Code oblige the interpreter of ordinary legislation, when it is true that the said Code does not occupy any prominent place in the legal system.

This question is answered by Professor Jorge Miranda, ibidem, p. 230, when he considers that the "[…] conclusion towards which one is inclined is that rules such as these are valid and effective not because they are contained in the Civil Code - for this does not occupy any prominent place in the legal system - but directly, as such, for translating a legislative will not contradicted by any other provisions regarding the problem of interpretation (which are not only technical-legal) with which they deal."

Adds the aforementioned author, idem, that "rules on these matters can be considered substantially constitutional and it would not even be surprising to see them raised to the Constitution in formal sense."

Regarding the problematic of interpretation and its rules, as drawn from Professor José de Oliveira Ascensão in The Law, Introduction and General Theory, 2nd edition, Calouste Gulbenkian Foundation, 1980, pp. 352/353, emphasis should be placed on the mandatory character of those rules and their binding nature for the interpreter.

The interpretation that the arbitral tribunal makes of article 3(1) of CIUC and the criteria that for this effect it considered, as expressly mentioned in the Decision issued in Case No. 196/2014-T, from the literal element to the systematic element, passing through the historical and rational (or teleological) element, do not collide thus with any constitutional principles.

Article 9(1) of the CC provides that the search for the legislative thought should take "[…] especially into account […] the unity of the legal system, the circumstances in which the law was elaborated and the specific conditions of the time in which it is applied", circumstances and conditions which today more than ever are of sensitivity to environment and of respect for questions related to it, and which are shown to be inscribed in the constitutional order.

Thus, given what is set forth above, it does not seem, with all due respect, that the Respondent is right, to the extent that the interpretation considered by the arbitral tribunal, as being the only one capable of respecting the legal purposes, does not violate any of the principles in question, that is, the principles of trust and legal certainty, of the efficiency of the tax system and of proportionality, and on the other hand such interpretation is expressly and substantively in accordance with the principles inscribed in the Constitution.

Thus, no conflict is apparent between the interpretation made by the tribunal regarding article 3(1) of CIUC and any constitutional norms or principles in force.

J - ACQUISITION OF THE OWNERSHIP OF THE VEHICLE AND THE VALUE OF THE REGISTRY

74 - First of all, it should be referred, regarding the value of the registry, that the acquirers of vehicles become owners of those same vehicles by way of the celebration of the corresponding purchase and sale contracts, with or without registry.

75 - There are three articles of the Civil Code that are important to take into account regarding the acquisition of ownership of a motor vehicle. They are, first of all, article 874, which establishes the notion of purchase and sale contract as being "[…] the contract by which the ownership of a thing or other right is transmitted, for a price"; article 879, in which letter a) it is established as essential effects of the purchase and sale contract, "the transmission of the ownership of the thing or the title of the right" and article 408, which bears the heading of contracts with real effect, and establishes in its paragraph 1 that "the constitution or transfer of real rights over a determined thing occurs by mere effect of the contract, save for the exceptions provided for in the law". (underlining ours)

We are, indeed, in the domain of contracts with real effect, which means that their celebration causes the transmission of real rights, in the case motor vehicles, determined by mere effect of the contract, as expressly results from the norm aforementioned.

76 - Regarding the aforementioned contracts with real effect, it is appropriate to note the teachings of Pires de Lima and Antunes Varela, when, in annotations to article 408 of the CC, they tell us that "From these contracts called real (quoad effectum), by having as immediate effect the constitution, modification or extinction of a real right (and not only the obligations tending towards that result), distinguish themselves the so-called real contracts (quoad constitutionem), which require the delivery of the thing as an element of their formation (see articles 1129, 1142 and 1185)".

We are thus faced with contracts in which the ownership of the thing sold is transferred, without more ado, from the seller to the buyer, having as cause the contract itself.

77 - Also from jurisprudence, in particular from the Judgment of the STJ No. 03B4369 of 19/02/2004, available at: www.dgsi.pt, it is drawn that in light of the provision of article 408(1) of the Civil Code, "the constitution or transfer of real rights over a determined thing occurs by mere effect of the contract, save for the exceptions provided for in the law". This is the case of the purchase and sale contract of a motor vehicle (articles 874 and 879(a) of the Civil Code), which does not depend on any special formality, being valid even when celebrated in verbal form - in accordance with Judgment of the STJ of 3-3-98, in CJSTJ, 1998, year VI, Part I, p. 117". (underlining ours)

78 - Having the purchase and sale contract, given what is set forth above, a real nature with the aforementioned consequences, it is also necessary to consider the legal value of the motor vehicle registry subject of that contract, to the extent that the transaction of the aforementioned good is subject to public registry.

79 - It establishes, indeed, article 1(1) of Decree-Law No. 54/75, of 12 February, relating to the registry of motor vehicles, that "The registry of vehicles has essentially as its purpose to give publicity to the legal situation of motor vehicles and respective trailers, with a view to the security of legal commerce". (underlining ours)

80 - Being clear, in light of the aforementioned norm, what the purpose of the registry is, there is not, however, clarity within the scope of the aforementioned Decree-Law regarding the legal value of that registry, it being important to consider article 29 of the aforementioned legal diploma, relating to the registry of motor vehicle ownership, when it provides that "Are applicable, with the necessary adaptations, to the registry of automobiles the provisions relating to property registry […]". (underlining ours)

81 - In this framework, in order that we may attain the sought knowledge regarding the legal value of the motor vehicle ownership registry it is important to take into account what is established in the Code of Property Registry, approved by Decree-Law No. 224/84 of 6 July, when it provides in its article 7 that "the final registry constitutes a presumption that the right exists and belongs to the registered title holder in the precise terms in which the registry defines it". (underlining ours)

82 - The combination of the provisions in the aforementioned articles, in particular that established in article 1(1) of Decree-Law No. 54/75 of 12 February and in article 7 of the Code of Property Registry, allows to consider, on one hand, that the fundamental function of the registry is that of giving publicity to the legal situation of vehicles, and allowing on the other hand to presume that the right exists and that such right belongs to the registered holder on whose behalf the registry is made, in the precise terms in which it is defined in the registry.

83 - Thus, the final registry constitutes nothing more than the presumption that the right exists and belongs to the registered title holder in the exact terms of the registry, but a rebuttable presumption admitting thus counter-proof as results from the law and jurisprudence has been pointing out, and to this effect can be seen among others the Judgments of the STJ Nos. 03B4369 and 07B4528, respectively of 19/02/2004 and 29/01/2008, available at: www.dgsi.pt.

84 - The function legally reserved to the registry is thus on one hand that of publicizing the legal situation of the goods in the case the vehicles and on the other hand allowing us to presume that the right over those vehicles exists and that it belongs to the registered title holder as such inscribed in the registry, which means that the registry does not have a constitutive nature of the right of ownership but only a declarative one, hence the registry does not constitute a condition of validity of the transmission of the vehicle from the seller to the buyer.

85 - Thus if the buyers of the vehicles as their "new" owners do not forthwith promote the adequate registry of their right it is presumed for purposes of article 3(1) of CIUC and of the provision in article 7 of the Code of Property Registry that the vehicles continue to be property of the person who sold them and who in the registry remains their owner being that person the passive subject of the tax in the certainty however that such presumptions are rebuttable either by virtue of the provision in article 350(2) of the CC or in light of the provision in article 73 of LGT. Hence that from the moment in which the presumptions in question are displaced by means of proof of the respective sale the AT cannot persist in considering as passive subject of IUC the seller of the vehicle who in the registry continues to appear as its owner.

L - MEANS OF PROOF PRESENTED

86 - Not being legally required the written form for the transmission of ownership of motor vehicles the proof of that transmission may be made by any means in particular by means of testimonial or documentary evidence included in the latter namely the invoices-receipts or the receipts relating to the sales of the vehicles.

87 - Regarding this matter it should be referred the aforementioned Judgment of the Central Administrative Court South issued on 19-03-2015 Case 08300/14 available at: www.dgsi.pt when it expressly understands regarding the invoice and the debit note that "[…] both documents appear in the phase of invoicing the amount to be paid by the buyer thus not making proof of payment of the price by the same buyer and as a consequence proof that the purchase and sale was concluded (only the issuance of invoice/receipt or receipt makes proof of payment and discharge - see article 787 of the Civil Code)" (underlining ours)

88 - As a means of proof that the vehicle with registration number ...-..-… was sold on 13-01-2006 it not being his property on the dates when the tax was exigible the Claimant attached a copy of the correspondence from the insurance company -B…, SA - relating to the aforementioned vehicle as well as a copy of the receipt for the sale of the said vehicle as scrap for the amount of € 200.00.

89 - Within the framework of the Mandatory System of Motor Vehicle Liability Insurance contained in Decree-Law No. 291/2007 of 21 August it is understood that a vehicle involved in an accident is considered to be in a situation of Total Loss as provided in article 41(1) of the aforementioned legal diploma when the obligation to indemnify is fulfilled in money and not through the repair of the vehicle whenever it is found that the repair is materially impossible or technically not advisable.

90 - This is what occurred in the case at hand to the extent that the aforementioned Insurer after the corresponding expert examination understood to regularize the situation of the damaged vehicle as Total Loss underlining as results from the correspondence attached to the case file the possibility of the Claimant being able to opt for the sale of the salvage.

91 - The vehicle in question was sold by the Claimant to the firm C… (…-…- Feira) as scrap on 13-01-2006 for the amount of € 200.00 a sum moreover superior to that which had been estimated by the insurer B… SA which attributed to the aforementioned vehicle/scrap the value of € 50.00 as results from the aforementioned documents being that the combination of the aforementioned documents allows to conclude in the sense that such transmission by the part of the Claimant occurred in reality.

92 - The transfer of the title of the vehicle as scrap to the aforementioned acquiring entity occurred thus on 13-01-2006 being that the exigibility of the corresponding IUC concerns the years 2008 to 2013.

93 - The information inscribed in the aforementioned documentation enjoys the presumption of veracity that in article 75(1) of LGT is conferred to it falling to the AT in light of the provision of article 75(2) of LGT within the framework of the grounded and objective reasons that it had to demonstrate that such information does not correspond to reality.

94 - Under these circumstances being AT exacting IUC relating to the years 2008 to 2013 and it not being the Claimant in these years the owner of the aforementioned vehicle it is considered that the aforementioned documentation (correspondence from the insurance company and receipt of sale) constitutes adequate and capable proof for rebutting the presumptions in question in the case file that is the presumption established in article 7 of the Code of Property Registry and that established in article 3(1) of CIUC which means that at the time the tax was exigible in all the aforementioned years (2008 to 2013) the Claimant was not a passive subject of IUC.

M - REPAYMENT OF THE AMOUNT PAID AND COMPENSATORY INTEREST

95 - It does not result from the documents attached to the proceedings nor from the administrative tax proceedings attached to the case file the alleged (undue) payment of the amount of € 1.391.80 which in light of the documentation made available in the case file is namely integrated by the sum of € 468.41 relating to IUC and to JC but only the payment of € 76.44 for purposes of IUC and compensatory interest. (see Doc. No. 14 of Doc. No. 2 presented with the request for arbitral decision)

96 - Under the terms of article 24(1)(b) of RJAT and in accordance with what is established therein the arbitral decision on the merit of the claim in which there is no right of appeal or challenge binds the tax administration from the end of the deadline provided for appeal or challenge with this - in the exact terms of the substantiation of the arbitral decision in favor of the passive subject and until the end of the deadline provided for the spontaneous execution of judgments of tax court decisions - "Restore the situation that would exist if the tax act subject of the arbitral decision had not been practiced adopting the acts and operations necessary for this purpose." (underlining ours)

97 - These are legal commands which are in complete harmony with the provision in article 100 of LGT applicable in the case by virtue of article 29(1)(a) of RJAT in which it is established that "The tax administration is obliged in case of full or partial substantiation of complaints or administrative appeals or judicial proceedings in favor of the passive subject to the immediate and full restoration of the situation that would exist if the illegality had not been committed including the payment of compensatory interest in the terms and conditions provided for in the law." (underlining ours)

98 - The case contained in the present proceedings raises the manifest application of the aforementioned norms being that in the sequence of the illegality of the assessment acts referenced in this proceeding will have by virtue of those norms of there to be in particular place to the repayment of the amounts paid either for purposes of tax or of compensatory interest as a form of achieving the restoration of the situation that would exist if the illegality had not been committed amounts which in the case at hand are concretized in the sum of € 76.44.

99 - As for compensatory interest it appears manifest that in light of the provision in article 61 of CPPT and with the requirements of the right to compensatory interest being met that is verified the existence of an error imputable to the services from which results payment of the tax debt in an amount superior to that legally due such as provided in article 43(1) of LGT the Claimant has the right to compensatory interest at the legal rate calculated on the aforementioned sum of € 76.44.

CONCLUSION

100 - Within the circumstantial framework that has been referred to the AT in practicing the assessment acts in question in the present proceedings founded on the idea that article 3(1) of CIUC does not establish a rebuttable presumption makes an incorrect interpretation and application of this norm committing an error regarding the legal prerequisites which constitutes a violation of law.

101 - On the other hand because the AT at the date of the occurrence of the tax facts considered the Claimant the owner of the vehicle referenced in the present proceedings considering it as such a passive subject of the tax when such ownership regarding the vehicle in question no longer existed in its legal sphere based thus on factual matter divergent from the actual reality commits an error regarding the factual prerequisites and therefore a violation of law.

III - DECISION

102 - Thus having regard to all that is set forth this Arbitral Tribunal decides:

• Not to examine by reason of matter the alleged illegality of the decisions relating to the application of the penalties nor the annulment of the enforcement proceedings and the costs and expenses associated with them opportunely instituted for collection of the tax debt in question;

• To judge partially substantiated as proven based on grounds of violation of law the request for arbitral decision as far as concerns the annulment of the IUC assessment acts relating to the years 2008 to 2013 concerning the vehicle identified in the case file;

• To annul consequently the acts of assessment of IUC with all the legal consequences flowing therefrom relating to the years 2008 to 2013 whose amounts ascend to the total of € 468.41 relating to the vehicle aforementioned;

• To condemn the AT either to the repayment of the sum of € 76.44 given that within the framework of the request for repayment of € 1.391.80 it is this the only amount relating to the tax in question whose payment is proven in the case file to the payment of the corresponding compensatory interest at the legal rate counted from the date of payment of the aforementioned sum until the full repayment of the same;

• To condemn the Claimant and the Respondent in costs which are fixed for each in the proportion of 66% for the Claimant and of 34% for the Respondent.

VALUE OF THE PROCEEDINGS

In accordance with article 306(2) of CPC (former 315(2)) and 97-A(1) of CPPT and article 3(2) of the Regulation of Costs in Tax Arbitration Proceedings the value of the proceedings is fixed at € 1.391.80.

COSTS

In accordance with article 12(2) at the end and article 22(4) both of RJAT and article 4 of the Regulation of Costs in Tax Arbitration Proceedings and the Table I attached thereto the amount of the total costs is fixed at € 306.00.

Notified.

Lisbon, 29 January 2016

The Arbitrator

António Correia Valente

(The text of this decision was prepared using a computer in accordance with article 131(5) of the Code of Civil Procedure (former 138(5)) applicable by referral of article 29(1)(e) of Decree-Law No. 10/2011 of 20 January (RJAT) its drafting being governed by the spelling prior to the Orthographic Agreement of 1990.)

[1] See the study on this matter, prepared by Professor Carlos Pestana Barros, in Science and Tax Technique, 2005, No. 416, pp. 105-126