Process: 19/2018-T

Date: June 4, 2018

Tax Type: Selo

Source: Original CAAD Decision

Summary

This CAAD arbitral decision (Process 19/2018-T) addresses the critical question of whether Stamp Duty under Item 28.1 of the General Stamp Duty Table (TGIS) applies to vertical property based on aggregate or individual unit values. The claimant owned a building in Lisbon with multiple independently usable residential divisions, each with a tax patrimonial value (VPT) below €1,000,000, but exceeding this threshold collectively. The Tax Authority assessed Stamp Duty on the total property value, while the claimant argued that each independent division should be assessed separately under IMI Code Article 12(3), which treats such divisions autonomously. The claimant contended that since IMI assesses each independent unit separately and Article 119(1) of the IMI Code requires itemized collection documents, the same treatment should apply for Stamp Duty purposes. The Tax Authority countered that properties in sole ownership differ fundamentally from condominium regimes where each autonomous unit constitutes a separate property under IMI Code Article 2(4). For Stamp Duty under Item 28.1 TGIS, the relevant factor is the entire property's residential allocation and aggregate VPT, not individual divisions. The Authority emphasized that while IMI may assess parts separately, Stamp Duty requires necessary adaptations for sole ownership properties, making the global value determinative. The claimant also sought reimbursement with compensatory interest from payment dates if successful. This case has significant implications for owners of vertical properties with multiple independent units, clarifying whether the €1,000,000 threshold applies per unit or to the building as a whole for annual Stamp Duty obligations.

Full Decision

ARBITRAL DECISION

REPORT

On 12 January 2018, A..., with the NIF..., resident at Avenue ..., no. ..., ..., in Lisbon (hereinafter referred to as the Claimant), came, pursuant to the provisions of articles 10 of Decree-Law no. 10/2011, of 20 January, which approved the Legal Framework for Arbitration in Tax Matters (RJAT) and 1 and 2 of Ordinance no. 112-A/2011, of 22 March (Binding Ordinance), to request the constitution of an Arbitral Tribunal, in which the Tax and Customs Authority (hereinafter AT or Respondent) is the Respondent, informing that it does not intend to exercise the faculty to appoint an arbitrator.

The request for constitution of the arbitral tribunal was accepted by His Excellency the President of CAAD on 15 January 2018 and automatically notified to AT, with the undersigned being designated by the CAAD Deontological Council as arbitrator of the Singular Arbitral Tribunal, a responsibility which she accepted within the legal period, without objection from the Parties.

A. Object of the Request:

The Claimant seeks the annulment of the order rejecting the request for official revision, as well as the declaration of illegality and consequent annulment of the Stamp Tax assessments (Item 28.1 of the TGIS) which were its subject, relating to the year 2015 and to the divisions susceptible of independent use and residential allocation of the urban property registered in the land register of the parish of ..., municipality of Lisbon, under article..., of which she is the owner, all in the total value of € 10,924.00 (ten thousand, nine hundred and twenty-four euros), value which she attributes to the request.

The Claimant further seeks that the Respondent be condemned to the restitution of the amounts unduly paid, plus compensatory interest from the date of payment of such amounts, until the issuance of the corresponding credit note.

B. Summary of the Positions of the Parties

Of the Claimant:

As grounds for the request to annul the acts of assessment of Stamp Tax (item 28.1 of the TGIS) relating to the year 2015 and to the property identified in the request for arbitral ruling, the Claimant invokes, in summary, the following:

The urban property of which the Claimant is the owner is composed of floors or divisions susceptible of independent use, whose tax patrimonial value (VPT) was assessed separately, in accordance with article 7, no. 2, subparagraph b), of the Real Estate Tax Code;

Although the VPT of the property, in its global amount, exceeds € 1,000,000.00, the VPT of each of the floors susceptible of independent use and residential allocation is less than € 1,000,000.00;

What is questioned is the exact meaning of the expression "tax patrimonial value considered for purposes of Real Estate Tax", included in the rule of application of Stamp Tax;

To determine the meaning of the said rule of application, recourse should be had to the rules of the Real Estate Tax Code relating to the treatment to be given to parts of urban properties susceptible of independent use, in accordance with article 12, no. 3, of the Real Estate Tax Code, which makes them autonomous for purposes of determining the VPT, in accordance with articles 38 and following of the same Code;

Autonomy which extends to the assessment of the tax, since article 119, no. 1, of the aforementioned Code, in determining that the collection document should itemize the properties and their parts susceptible of independent use and respective VPT, requires that the sum of the VPTs not be taken as reference, but rather the VPT attributed to each of them;

Being the VPT of each division of independent use the value relevant for purposes of Real Estate Tax assessment, it will be this value to be considered in the assessment of Stamp Tax of item 28.1 of the TGIS;

The request for official revision of the assessments under analysis should not have been rejected, since these suffer from a defect of error in the factual and legal presuppositions attributable to AT;

From such attribution it results that interest is owed from the date on which it proceeded to payment of each of the assessed installments.

Of the Respondent:

Notified in accordance with the terms and for the purposes provided in article 17 of the RJAT, AT presented its response and attached the administrative file, defending, by way of objection, the legality and maintenance of the assessment acts subject to the present request for arbitral ruling, with the grounds which, briefly summarized, are as follows:

The Claimant petitions for a declaration of illegality of the Stamp Tax assessments (item 28.1 of the TGIS) relating to the urban property in sole ownership identified in the request for arbitral ruling;

However, the subjection to Stamp Tax results from the combination of the factors residential allocation and VPT of the property registered in the land register, equal to or exceeding € 1,000,000.00;

The property to which the request for arbitral ruling relates is registered in the land register under the sole ownership regime and, in accordance with article 23, no. 7, of the Tax Code, the assessment in question took into account the nature of the property on the date of the tax event, namely its residential allocation divisions, applying, with the necessary adaptations, the rules of the Real Estate Tax Code;

The concept of property is defined in article 2, no. 1, of the Real Estate Tax Code, with its no. 4 providing that, under the condominium ownership regime, each autonomous unit is deemed to constitute a property; from this it follows that a property in sole ownership, with floors or divisions susceptible of independent use is, unequivocally, different from a property under the condominium regime, constituted by autonomous units, or rather, by several properties;

Article 12, no. 3, of the Real Estate Tax Code concerns, exclusively, the manner of recording the land register data and, as regards Real Estate Tax assessment, when dealing with properties in sole ownership, the value which serves as the basis for its calculation will be that which the Claimant defines as the "global value of the property", although the collection document is sent to the taxpayer with itemization of the parts susceptible of independent use and respective tax patrimonial value (article 119, no. 1, of the Real Estate Tax Code);

The Claimant argues that there is no rule corresponding the VPT of a property in sole ownership to the sum of the VPTs of its divisions of independent use;

However, this thesis lacks legal support, since in the situations provided for in item no. 28.1 of the TGIS, the legislator reserves those aspects that require the necessary adaptations, as is the case of properties in sole ownership, with floors or divisions susceptible of independent use in which, although the Real Estate Tax is assessed in relation to each part susceptible of independent use, for purposes of Stamp Tax what is relevant is the property in its entirety since the divisions susceptible of independent use are not deemed to be a property;

By the foregoing, the invoked defect of breach of law should be judged to be unfounded, and the assessments under challenge should be maintained, as they constitute a correct application of the law to the facts.

AT concludes by requesting the waiver of the meeting referred to in article 18 of the RJAT, as well as of the production of written pleadings, since the facts upon which a decision is requested are established and the matter is exclusively one of law.

Notified for this purpose, the Claimant presented its written pleadings, in which it reiterated the position assumed in the request for arbitral ruling.

Also notified, the Respondent did not file a counter-reply.

II. EXAMINATION OF PRELIMINARY ISSUES

The singular arbitral tribunal is competent and was regularly constituted on 20 March 2018, in accordance with articles 2, no. 1, subparagraph a), 5 and 6, all of the RJAT.

The parties have legal personality and capacity, are entitled and are legally represented, in accordance with articles 4 and 10 of the RJAT and article 1 of Ordinance no. 112-A/2011, of 22 March.

The proceedings do not suffer from defects that would invalidate them.

The cumulation of claims is admissible, in accordance with the provisions of no. 1 of article 3 of the RJAT, insofar as the request for arbitral ruling formulated and its admissibility depend on the assessment of the same factual circumstances and on the interpretation and application of the same legal principles and rules, in this case, item 28.1 of the General Table of Stamp Tax.

No exceptions were invoked that the Singular Arbitral Tribunal is competent to assess and decide.

III. REASONING

III.1 FACTUAL MATTER

Proven Facts

The factual matter relevant to the understanding and decision of the case, after critical examination of the documentary evidence and the administrative file attached to the records, is established as follows:

On the date of the occurrence of the tax event (31 December 2015), the Claimant was the owner of the urban property registered in the land register of the parish of ..., municipality of Lisbon, under article..., with the total tax patrimonial value of € 1,338,423.75 (cf. copy of the land register notebook attached to the administrative file);

The said property, in sole ownership, was composed of 16 floors or divisions of independent use, 1 of which intended for warehouse; 3, for commerce; 2, for services and 10, for residential purposes (cf. copy of the land register notebook attached to the administrative file);

The Tax Patrimonial Value of each of the floors or divisions of independent use, from the first to the fifth floors, allocated to residential purposes, was, in the year to which the tax relates, € 109,240.00 (cf. copy of the land register notebook attached to the administrative file);

The Claimant was notified of the assessment of Stamp Tax of item 28.1 of the General Table of Stamp Tax, relating to the year 2015, at the rate of 1%, on the VPT of the 10 floors or divisions of independent use intended for residential purposes, in the total value of € 10,924.00 (cf. the extract relating to "Stamp Tax – Consultation of Assessments of Item 28", attached to the administrative file);

On 31 May 2017, the Claimant filed, at the Finance Office of Lisbon ..., pursuant to the provisions of article 78, no. 1, of the General Tax Law, a request for official revision of the Stamp Tax assessments now under challenge, there registered under no. ...2017... and forwarded to the Administrative Justice Division of the Finance Directorate of Lisbon, for decision (cf. pages 4 and following of the administrative file);

The request for official revision was rejected by order of the Assistant Finance Director of Lisbon, of 18 December 2017, notified to the Claimant through the person of her Court-appointed Attorney by means of memorandum no. ... of the Administrative Justice Division of the Finance Directorate of Lisbon, of 21 December 2017 (Post Office Registry no. RD ... PT, of 22/12/2017 – copy attached at pages 27 and 28 of the administrative file);

In the report on which the order rejecting the request for official revision was based, the respective procedural presuppositions were analyzed and the merits of the request were assessed, in particular, with the following grounds: "(…) 'vii. From the analysis of the situation at hand in the records, it appears to us that the property subject of the present proceeding is a property in sole ownership with floors or divisions susceptible of independent use (units), which together have a tax patrimonial value exceeding € 1,000,000.00 and predominantly residential allocation.'; 'viii. Now in the present case the tax patrimonial value of the property exceeds the required amount and there is residential allocation of the same, even if not exclusively, but the law does not require that the residential allocation be exclusive to all economically autonomous parts of the same property' (…)" (cf. pages 24 to 26 of the administrative file);

The Claimant proceeded to pay the collection notices relating to all the installments which were notified to her (cf. computer extract at page 16 of the administrative file).

Unproven Facts and Justification for Establishment of Factual Matter

There are no facts relevant to the decision of the case which have not been proven.

The proven facts, which are not disputed, are based on the documents attached by the Claimant with the request for arbitral ruling and the administrative file attached by the Respondent.

III.2 OF LAW

The Question to be Decided

The question brought before the tribunal by the Claimant is whether the expression "tax patrimonial value recorded in the land register, in accordance with the Real Estate Tax Code (CIMI)", referred to in item no. 28 of the General Table of Stamp Tax (TGIS), added by Law no. 55-A/2012, of 29 October, refers to the Tax Patrimonial Value (VPT) of each of the economically independent parts with residential allocation of an urban property not constituted under the condominium regime, as she argues, or whether it is determined by the global VPT of the property, which would correspond to the sum of all the VPTs of the floors or divisions of independent use and with residential allocation that compose it, in accordance with the interpretation given by AT to the said rule.

On the Merits of the Stamp Tax Assessments for the Year 2015

Item 28.1 of the TGIS, in the wording given to it by Law no. 83-C/2013 of 31 December (State Budget for 2014), applicable to the assessments under challenge, established the subjection to Stamp Tax of the ownership, usufruct or right of superficies of residential urban properties or land for construction the construction of which, authorized or envisaged, was for residential purposes and whose VPT recorded in the land register, in accordance with the Real Estate Tax Code (CIMI), was equal to or exceeding € 1,000,000.00.

The concepts of urban property and residential urban property are defined in the CIMI, of subsidiary application to matters relating to item 28 of the TGIS, by virtue of the cross-reference made by no. 2 of article 67 of the Stamp Tax Code, in the wording at the date of the facts.

Property is, in the definition of article 2 of the CIMI, "any fraction of territory, including waters, plantations, buildings and constructions of any nature incorporated therein or established thereon, with a character of permanence, provided that it forms part of the patrimony of a natural or legal person and, in normal circumstances, has economic value, as well as waters, plantations, buildings or constructions, in the circumstances above, endowed with economic autonomy in relation to the land where they are established, even though situated on a fraction of territory that constitutes an integral part of a patrimony other than themselves or does not have a patrimonial nature" (no. 1) and also autonomous units of properties constituted under the condominium ownership regime (no. 4).

For its part, article 4 of the CIMI defines residually as urban, all those that are not classified as rural or mixed.

There are, however, various types of urban properties, whose classification is established by article 6 of the CIMI, whose no. 1 classifies them as a) residential, b) commercial, industrial or for services, c) land for construction and d) others, with nos. 2, 3 and 4 of the same article delimiting what should be understood by each of those designations.

Residential properties are therefore buildings or constructions licensed for residential use or which, in the absence of a license, have as their normal purpose residential use (residential purposes).

Now, the property of which the Claimant is the owner was, on the date of the occurrence of the tax event, an urban property not constituted under the condominium regime, which comprised floors or divisions of independent use, some intended for residential purposes and others for "warehouse" or commercial purposes.

As regards the determination of the tax patrimonial value of properties with parts that may be classified in more than one of the classifications of no. 1 of article 6 of the CIMI, as is the case of the property identified in the records, article 7, no. 2, subparagraph b), of the same Code applies, which provides that "Should the different parts be economically independent, each part shall be evaluated by application of the corresponding rules, with the value of the property being the sum of the values of its parts."

And this is the only rule of the Real Estate Tax Code in which reference is made to the "value [global] of the property", without, however, this having any relevance at the level of tax assessment, since each floor or part susceptible of independent use "is considered separately in the land register entry, which also itemizes the respective tax patrimonial value" (article 12, no. 3, of the CIMI), with AT having issued individualized assessments for each floor or division of independent use and not a single assessment on the "global value" of the property.

On the other hand, the urban property of which the Claimant is the owner and which is the subject of the present proceedings, comprising floors or divisions susceptible of independent use, some intended for residential purposes and others for purposes other than residential, cannot, globally, be considered a residential urban property, as is indeed recognized by AT in the reasoning of the order rejecting the request for official revision which was the subject of the Stamp Tax assessments now under challenge.

Now, contrary to what was decided in administrative proceedings, it does not appear acceptable that the floors or divisions allocated to residential purposes, which form part of the said urban property, should be segregated from the whole, so that, as a group, they might be comprised within the notion of residential urban property provided in the rule of application of item 28.1 of the TGIS.

It cannot therefore be accepted that, by so doing, AT formulates a rule of application ex novo, different from that created by the legislator, at the risk of violation of the principle of tax legality, inherent in article 103, no. 2, of the Constitution of the Portuguese Republic.

What appears to result from the ratio legis underlying the rule of item 28 of the TGIS, introduced by Law no. 55-A/2012 of 29 October, is that the legislator intended to tax the ownership, usufruct and right of superficies of residential units with a VPT equal to or exceeding € 1,000,000.00, as an index of high contributive capacity.

Now, as it results from the proven facts, none of the floors or divisions susceptible of independent use and residential allocation which are the subject of the assessments under analysis had a VPT equal to or exceeding that defined in the rule of application, and it should be concluded that they are excluded from it.

Furthermore, the following is the consolidated case law of the Supreme Administrative Court (cf. the Judgment of the Plenary Session of 29/03/2017, proc. no. 0593/16, available at www.dgsi.pt), to which with due respect reference is made and to which adherence is given:

"I - Item 28 of the General Table of Stamp Tax (TGIS) added by art. 4 of Law no. 55-A/2012, of 29/10, does not apply to urban properties with a single land register entry but constituted by parts with independent allocation and use to each of which independent VPTs were attributed, each of these of a value less than one million euros.

II - As item 28 of the General Table has not made any distinction between properties under the condominium regime and sole/vertical ownership and refers to the tax patrimonial value used for purposes of Real Estate Tax, it shall not be the duty of the person applying it to introduce any distinction, all the more so since it is a rule of application.

III - If it had been the legislator's intention to tax properties which, having a single land register entry, because they are constituted by parts susceptible of independent use have attributed various tax patrimonial values, and intended that for purposes of taxation in the context of Stamp Tax, in this case, account be taken of the sum of those various tax patrimonial values, it would not have added the final part of the provision: on the tax patrimonial value used for purposes of Real Estate Tax.

IV - Nothing in the law imposing the consideration of any sum of all or part of the VPTs attributed to the various parts of a property with a single land register entry also shows it to be inconsistent with the law to perform such arithmetic operation only for the purpose of the taxation provided for in item 28 of the General Table of Stamp Tax".

For the reasons set out, having verified the defect of breach of law, by error in the application of law, arising from the incorrect interpretation of the rule of application of item no. 28.1 of the TGIS, it must be concluded that the assessments under challenge cannot be maintained in the legal order.

On the Request for Compensatory Interest

In accordance with the provisions of no. 1 of article 43 of the General Tax Law (LGT), applicable subsidiarily to tax arbitration proceedings, in accordance with article 29, no. 1, subparagraph a), of the RJAT, "Compensatory interest is owed when it is determined, in gracious reclamation or judicial challenge, that there was error attributable to the services resulting in payment of the tax debt in an amount exceeding that legally due."

The cumulative requirements for the right to compensatory interest are therefore: "– that there be an error in an act of assessment of a tax; – that it be attributable to the services; – that the existence of this error be determined in a process of gracious reclamation or judicial challenge; – that as a result of this error payment of a tax debt in an amount exceeding that legally due has been made."[1]

However, the scope of the right to compensatory interest, in the case of a request for official revision of the tax act, is not as broad as that which results from no. 1 of article 43 of the LGT, but rather comes down to the provision of no. 3, subparagraph c), of the same article, whereby compensation is owed "When the revision of the tax act at the initiative of the taxpayer is effected more than one year after the request thereof, except if the delay is not attributable to the tax administration".

The justification for the distinction regarding the initial date for counting compensatory interest owed to the taxpayer in one case and the other arises from the fact that, in situations where the illegality of the tax act, by error attributable to the services, is invoked in a request for revision, in accordance with article 78, no. 1, of the LGT, even though judicial challenge may subsequently be filed, as has occurred in the case of the present proceedings, an "(…) extensive period has elapsed in which the restoration of legality could have been brought about at the initiative of the taxpayer who did not pursue it, which justifies that the right to compensatory interest must be of a more limited scope as opposed to the situation in which the taxpayer raises the question of the illegality of the assessment act immediately after the disbursement of the amount in question", therefore, "The legislator considers that the period of one year is the reasonable period for the Administration to decide on the request for revision and execute the respective decision, when favorable to the taxpayer, departing from full compensation of damages from the moment they arose in the taxpayer's patrimonial sphere." – cf. the Judgment delivered by the Supreme Administrative Court, on 28 January 2015, Process no. 0722/14, available at www.dgsi.pt).

Thus, although considering that the assessments under challenge in the present proceedings suffer from a defect of breach of law, by error in the legal presuppositions, attributable to the Respondent, which justifies their annulment, compensatory interest is recognized only on the amounts paid from the date of expiration of the period of one year from the date of the request for its official revision, filed on 31 May 2017, until the issuance of the respective credit note in favor of the Claimant.

DECISION

Based on the factual and legal grounds set out above and, in accordance with article 2 of the RJAT, the following decision is rendered, judging the present request for arbitral ruling to be entirely admissible:

Declare the illegality of the Stamp Tax assessments (item 28.1 of the TGIS) under challenge, by error in the legal presuppositions, determining their annulment;

Declare the illegality of the order rejecting the request for official revision of the annulled assessments;

Condemn AT to the restitution of the amounts unduly paid by the Claimant as Stamp Tax for 2015, plus compensatory interest, in accordance with article 43, no. 3, subparagraph c), of the LGT.

VALUE OF THE PROCEEDINGS: In accordance with the provisions of article 306, nos. 1 and 2, of the Code of Civil Procedure, 97-A, no. 1, subparagraph a), of the Tax Code of Procedure and Process and 3, no. 2, of the Regulation of Costs in Tax Arbitration Proceedings, the proceedings are valued at € 10,924.00 (ten thousand, nine hundred and twenty-four euros).

COSTS: Calculated in accordance with article 4 of the Regulation of Costs in Tax Arbitration Proceedings and Table I annexed thereto, in the amount of € 918.00 (nine hundred and eighteen euros), at the charge of the Tax and Customs Authority.

Let notification be made.

Lisbon, 4 June 2018.

The Arbitrator,

/Mariana Vargas/

Text prepared by computer, in accordance with no. 5 of article 131 of the Code of Civil Procedure, applicable by cross-reference of subparagraph e) of no. 1 of article 29 of Decree-Law 10/2011, of 20 January.

The wording of this decision is governed by the 1990 Orthographic Agreement.

[1] Cf. SOUSA, Jorge Lopes de, Code of Tax Procedure and Process – annotated and commented, Volume I, Áreas Editora, 2006, page 472.

Frequently Asked Questions

Automatically Created

Does Stamp Duty under Verba 28.1 of TGIS apply to a building's total patrimonial value or to each independent unit's value separately?
Stamp Duty under Verba 28.1 of TGIS applies to the total patrimonial value of a building in sole ownership, not to each independent unit separately. The Tax Authority's position, which prevailed, establishes that while the IMI Code may assess divisions independently under Article 12(3), for Stamp Duty purposes the relevant threshold is the aggregate VPT of the entire property. The distinction lies in ownership structure: properties under condominium regime have separate autonomous units (each a distinct property), whereas sole ownership properties with independent divisions remain a single property despite internal divisions. The €1,000,000 threshold therefore applies to the sum of all divisions' values, not individually.
How are independently usable divisions of a vertical property assessed for Stamp Duty purposes when individual unit values are below €1,000,000?
Independently usable divisions of a vertical property are assessed for Stamp Duty purposes by aggregating their individual tax patrimonial values to determine if the €1,000,000 threshold is met. Even when each division's VPT falls below €1,000,000, if the combined total exceeds this amount, Stamp Duty under Item 28.1 TGIS applies to the entire property. The Tax Authority applies 'necessary adaptations' of IMI Code rules for Stamp Duty, meaning that while IMI may itemize divisions separately on collection documents (Article 119(1) IMI Code), this administrative practice does not fragment the property into separate taxable units for Stamp Duty. The property's residential allocation and global VPT determine tax liability.
Can a taxpayer request a review (revisão oficiosa) to challenge Stamp Duty assessments on vertical property under Portuguese tax law?
Yes, taxpayers can request official review (revisão oficiosa) to challenge Stamp Duty assessments on vertical property, as demonstrated in this case. The claimant invoked this administrative remedy arguing error in factual and legal presuppositions by the Tax Authority. When the review request was rejected, the claimant escalated to CAAD arbitration under the Legal Framework for Arbitration in Tax Matters (RJAT). If successful in proving illegality of the assessments, the taxpayer would be entitled to reimbursement of amounts unduly paid plus compensatory interest calculated from the payment date of each installment until issuance of the credit note, as explicitly requested in the arbitral proceeding.
What role does Article 12(3) of the IMI Code play in determining Stamp Duty liability for buildings with multiple independent units?
Article 12(3) of the IMI Code plays a limited role in determining Stamp Duty liability for buildings with multiple independent units. While this provision establishes that parts of urban properties susceptible of independent use should be registered autonomously in land registry data and assessed separately for IMI purposes, the Tax Authority successfully argued this autonomy does not automatically extend to Stamp Duty under Item 28.1 TGIS. The provision primarily governs IMI assessment methodology and land registry recording practices. For Stamp Duty on sole ownership properties, the legislation requires considering the property 'in its entirety' with necessary adaptations from IMI rules, meaning the aggregate VPT determines whether the €1,000,000 threshold triggering annual Stamp Duty is met.
Is the property owner entitled to reimbursement with compensatory interest if Stamp Duty on vertical property is declared illegal by CAAD?
Property owners are entitled to reimbursement with compensatory interest if Stamp Duty on vertical property is declared illegal by CAAD. The claimant specifically requested not only annulment of the Stamp Duty assessments totaling €10,924.00 but also condemnation of the Tax Authority to restore unduly paid amounts plus compensatory interest. The interest calculation would run from the date of payment of each installment until issuance of the corresponding credit note. This remedy flows from the principle that when tax assessments are annulled due to illegality attributable to the Tax Authority, the state must compensate taxpayers for the time value of money improperly collected, recognizing the financial burden imposed during the period between unlawful collection and restitution.