The Catastro's reference value: the floor under transfer and inheritance tax, how it is built, where to look it up before you sign and how to challenge it after the Constitutional Court's 2026 ruling

A couple from Germany signs for a second-hand apartment in Corralejo in November 2026 at €180,000, the price the seller accepted after three months on the market. Stapled to the deed is a certificate the notary pulled from the Catastro that nobody mentioned during the negotiation: the property's reference value, €205,000. Their transfer tax is not 6.5 % of what they paid but 6.5 % of that figure, €13,325 instead of €11,700, and the €1,625 difference is tax on €25,000 that changed hands nowhere. Since 1 January 2022 that certificate has decided the taxable base of every second-hand purchase, every inheritance and every gift of real estate in Spain. This article explains what the reference value is and how the Catastro builds it each year, which taxes it floors and which it leaves alone, where to look it up before signing and what happens when a property has none, what the Corralejo couple actually pays, the two routes the law gives to challenge the figure and the file each one needs, what the Constitutional Court decided in February 2026, the question the Supreme Court admitted in April 2026 from a Tenerife case and has yet to answer, and what the regional courts have accepted and rejected as proof.

What the reference value is, and how the Catastro builds it

The reference value is not the cadastral value, and it is not an appraisal of your flat. It is a figure the Dirección General del Catastro assigns to every property it can, once a year, from the prices notaries report in real sales. The rule is the third final provision of the cadastre act, Real Decreto Legislativo 1/2004, in the wording the anti-fraud Act, Ley 11/2021, gave it: the Catastro determinará de forma objetiva y con el límite del valor de mercado, a partir de los datos obrantes en el Catastro, el valor de referencia, resultante del análisis de los precios comunicados por los fedatarios públicos en las compraventas inmobiliarias efectuadas, will determine objectively, capped at market value and from the data it holds, the reference value that results from analysing the prices notaries report in the sales actually made. The analysis goes into un informe anual del mercado inmobiliario, y en un mapa de valores que contendrá la delimitación de ámbitos territoriales homogéneos de valoración, an annual report on the property market and a map of values that divides the territory into homogeneous valuation areas, each with an average value module for its representative property. So that the result stays under the market, the Act orders un factor de minoración al mercado para los bienes de una misma clase, a reduction factor for each class of property, and Orden HFP/1104/2021 fixed it: for urban property en su determinación será de aplicación el factor de minoración (FM) 0,9, a factor of 0.9 is applied in its determination, and the same 0.9 for rural land. The Catastro's own answer to the question why a value changed on 1 January is that El valor de referencia de los inmuebles se determina, año a año, the reference value of properties is determined year by year, from the sales of the year before.

How the module becomes your flat's figure is, for now, borrowed from the cadastral valuation rules. The ninth transitional provision says that until a regulation is approved, for urban property los criterios y reglas de cálculo se ajustarán a lo previsto en las normas técnicas de valoración y cuadro marco de valores del suelo y de las construcciones para determinar el valor catastral de los bienes inmuebles de naturaleza urbana, the criteria and rules of calculation follow the technical valuation norms and the framework of land and construction values used for the cadastral value of urban property. The Catastro's questions and answers put it in plainer words: the value of a specific property is calculated from the module of its area teniendo en cuenta entre otras, las diferencias de categorías, antigüedad y estado de conservación entre este inmueble y el producto inmobiliario representativo al que se refiera el módulo, taking into account, among other things, the differences in category, age and state of repair between this property and the representative one the module describes. Nobody visits. The figure comes from what the Catastro has on file about your building: surface, year, quality, use. If the file is wrong, the value is wrong, and that is the first thing to check.

The calendar is written in the Act. Each year the Catastro approves a resolution with the elements needed to compute the next year's values, and Esta resolución se publicará por edicto en la Sede Electrónica de la Dirección General del Catastro antes del 30 de octubre del año anterior a aquel en que deba surtir efecto, previo trámite de audiencia colectiva, it is published by edict on the Catastro's e-office before 30 October of the year before it takes effect, after a collective hearing announced in the BOE for ten days. In the first twenty days of December the Catastro publishes an anuncio informativo para general conocimiento de los valores de referencia de cada inmueble, an information notice so that everyone knows the values of each property. The 2026 cycle ran exactly so. The BOE of 8 October 2025 announced la apertura del trámite de audiencia colectiva previo a la aprobación de la resolución de la Dirección General del Catastro sobre elementos precisos para la determinación de los valores de referencia de los bienes inmuebles urbanos del ejercicio 2026, the opening of the hearing before the resolution on the elements for the 2026 urban values; the resolution is dated 27 October 2025; and the notice in the BOE of 16 December 2025 said that the values podrán ser consultados de forma permanente en la Sede Electrónica del Catastro, may be consulted permanently on the Catastro's e-office, from 1 January 2026. On 21 October 2026 the same e-office already listed the market reports and procedures for 2027, published on 25 September 2026: the values that will govern deeds signed from 1 January 2027 are being settled now, and a purchase that slips from December into January can change its base without anyone touching the price.

One thing the value does not do, in the Catastro's words: El valor de referencia no afecta al valor catastral vigente en modo alguno, it does not affect the cadastral value in force in any way. Your IBI does not move.

The taxes it floors, and the one it does not touch

The reference value matters because three tax Acts were rewritten in 2021 to point at it. For transfer tax, article 10 of Real Decreto Legislativo 1/1993 keeps market value as the general base, defined as el precio más probable por el cual podría venderse, entre partes independientes, un bien libre de cargas, the most probable price at which a property free of charges could be sold between independent parties, and then carves out real estate: En el caso de los bienes inmuebles, su valor será el valor de referencia previsto en la normativa reguladora del catastro inmobiliario, a la fecha de devengo del impuesto, for real estate the value is the reference value under the cadastre rules at the date the tax accrues. Accrual, under article 49, is el día en que se realice el acto o contrato gravado, the day the act or contract is made: the date of the deed, not of the private contract or of the handover of keys. The floor works one way only: si el valor del bien inmueble declarado por los interesados, el precio o contraprestación pactada, o ambos son superiores a su valor de referencia, se tomará como base imponible la mayor de estas magnitudes, if the declared value or the agreed price, or both, exceed the reference value, the higher figure is the base. Pay more than the Catastro thinks and you are taxed on what you paid; pay less and you are taxed on what the Catastro thinks. Article 46 closes the circle: the administration may check values salvo que, en el caso de inmuebles, la base imponible sea su valor de referencia o magnitud superior, except where the base of a property is its reference value or a higher figure, so a buyer who files on the reference value will not receive a value check afterwards.

Inheritance and gift tax follows the same design in article 9 of Ley 29/1987: the base of an inherited or gifted property is its reference value at the date of death or of the gift, and si el valor del bien inmueble declarado por los interesados es superior a su valor de referencia, se tomará aquel como base imponible, if the heirs declare more, their figure is the base; article 18 bars a value check salvo que, en el caso de inmuebles, la base imponible sea su valor de referencia o el valor declarado por ser superior, except where the base is the reference value or a higher declared value. How the Canary inheritance and gift returns are filed, where and within which deadlines is the subject of our article on modelos 650 and 651, and the arithmetic of giving a home to a child against leaving it in the will is in our colleagues' piece on gifts to children in the Canaries.

Stamp duty got a floor too. Article 30 of the transfer-tax text, for notarial deeds whose base depends on a property's value, now says Cuando la base imponible se determine en función del valor de bienes inmuebles, el valor de estos no podrá ser inferior al determinado de acuerdo con lo dispuesto en el artículo 10 de este texto refundido, where the base is determined by the value of real estate, that value cannot be lower than the article 10 figure. That reaches the deed of a new home bought from its developer, which pays IGIC instead of transfer tax and stamp duty on top. The IGIC itself is untouched, because article 22 of Ley 20/1991 sets its base at el importe total de la contraprestación de las operaciones sujetas al mismo procedente del destinatario o de terceras personas, the total consideration received from the buyer or from third parties, that is, the price; the stamp duty on the same deed, however, cannot be computed below the reference value where the new building already has one. Many new builds have none at the date of the deed, because the Catastro has not yet described them, and the next section says what happens then.

Wealth tax is reached indirectly. Article 10 of Ley 19/1991 values real estate Por el mayor valor de los tres siguientes: El valor catastral, el determinado o comprobado por la Administración a efectos de otros tributos o el precio, contraprestación o valor de la adquisición, at the highest of three figures: the cadastral value, the value determined or checked by the administration for other taxes, and the acquisition price. The Catastro's reading is that a reference value that served as the base of the purchase or inheritance tax is such a value, and only from then on: el valor de referencia sólo podrá afectar al Impuesto sobre el Patrimonio en lo que se refiera a inmuebles adquiridos a partir de 1 de enero de 2022, en ningún caso al patrimonio preexistente, it can affect wealth tax only for properties acquired from 1 January 2022, never pre-existing holdings. Whether the figure then pushes a non-resident owner over the wealth-tax threshold is a question for the year's return, not for the deed.

In the Canaries the general transfer-tax rate, article 31 of Decreto Legislativo 1/2009, is con carácter general el tipo del 6,5%, 6.5 % as a general rule, and the 5 % track for a habitual residence requires that the base, garages and annexes in the same building included, sea inferior o igual a 200.000 euros, be €200,000 or less. Because the test is on the base and the base is the higher of price and reference value, a reference value above €200,000 shuts the track even when the price is under it. Both tracks, the 20 % bonus and the IGIC tracks for new builds are worked through in our guide to buying a home in Fuerteventura in 2026. The return is the buyer's: article 39 gives un mes a contar desde el momento en que se cause el acto o contrato, one month from the act or contract, to file Modelo 600 with the Agencia Tributaria Canaria. The seller's side of the same deed, the gain and the municipal plusvalía, is a different article, our piece on selling a home in Fuerteventura as a tax resident.

Looking the value up before you sign, and what to do when there is none

The value is public and dated. The Catastro's e-office lets anyone consultar y certificar el valor de referencia de un inmueble a una determinada fecha, consult and certify a property's reference value at a given date, after identifying themselves por medio de los datos de su Documento Nacional de Identidad, con certificado digital, o a través de Cl@ve, with the data of a Spanish identity document, a digital certificate or Cl@ve. A foreign buyer with none of these asks the notary, the agent or an adviser to pull it, or calls the Línea Directa del Catastro, which gives the figure by phone. The certificate shows the value and the date it is valid for, which must be the date of the deed. Owners get more: un certificado de motivación del valor de referencia a una determinada fecha, de manera que dispongan de todos los datos y elementos técnicos empleados para su determinación, a reasoned certificate with every datum and technical element used to compute it, which is where a surface twenty square metres too large, a year of construction twenty years too young or a quality category two steps too high come to light. Those are not tax matters; they are description errors, and the Catastro's answer is that the owner may at any time file declarations or, en caso de disconformidad con los datos descriptivos del inmueble inste, ante la Dirección General del Catastro, los procedimientos catastrales previstos en la norma, where he disagrees with the descriptive data, start the cadastral procedures before the Catastro. Corrected data give a corrected value for the next deed; they do not reopen a tax already paid, for which the routes below exist.

Not every property has a value. The Catastro says so: No existe valor de referencia para los inmuebles que no se encuentren incluidos en el ámbito de aplicación de la correspondiente resolución de la Dirección General del Catastro sobre elementos precisos para la determinación del valor de referencia, o cuando concurran las causas de tipo técnico que se prevean en la misma, there is no reference value for properties outside the scope of the year's resolution or where the technical causes it foresees apply, and Este hecho no tiene ningún efecto, jurídico o fiscal, por sí mismo, this fact has no legal or tax effect of its own. The urban maps the Catastro publishes are the residential and the garage-parking ones, and the rural resolution covers rural land without buildings, so a commercial unit, a plot, a building still under construction or a country house on rural land commonly has none. Article 10 then falls back to the old world: Cuando no exista valor de referencia o este no pueda ser certificado por la Dirección General del Catastro, la base imponible, sin perjuicio de la comprobación administrativa, será la mayor de las siguientes magnitudes: el valor declarado por los interesados, el precio o contraprestación pactada o el valor de mercado, where no reference value exists or can be certified, the base is the higher of the declared value, the price and the market value, subject to an administrative check. That check is the comprobación de valores of article 57 of the General Tax Act, and the Supreme Court has spent 2026 policing it. In a line of judgments that ends, for now, with judgment 1025/2026 of 21 September 2026 it repeated that the agency may open a check on the gap between the price and the bank's mortgage appraisal sin que le sea exigible ninguna carga adicional respecto a los demás medios de comprobación de valores, without any extra burden compared with the other means of checking; in judgment 923/2026 of 16 July 2026 it held that when the agency values by expert report esa visita o comprobación debe implicar, de manera necesaria e inexorable, tanto el examen del exterior como del interior del inmueble, the expert's visit must as a rule cover the outside and the inside of the property, with any exception justified in the file. Buyers of a plot or an unfinished house in Fuerteventura should therefore keep the appraisal and the photographs of the day of the deed; they may need them within four years.

Worked example: €180,000 paid, €205,000 reference, Corralejo

Back to the couple. The deed is signed in November 2026, the Catastro certifies €205,000 for that date, the price is €180,000. The table does the arithmetic at the Canary rates.

They file Modelo 600 within the month on €205,000 and pay €13,325. If they believe the flat is not worth €205,000, they have a decision to make, and the Tenerife buyer whose case is now before the Supreme Court made it the way most notaries recommend. Her deed records that she para evitar problemas y por exigencias de la entidad financiera procederá a liquidar el impuesto por el valor de referencia, superior al precio y al valor de tasación del inmueble reservándose el derecho de reclamar la devolución de lo pagado por encima del precio, would pay the tax on the reference value, higher than the price and than the appraisal, to avoid problems and because the bank required it, reserving the right to claim back what she paid above the price. Paying first and asking for rectification costs the money for some months, and interest comes back with it if she wins. Declaring €180,000 saves the cash now and invites a liquidation for the difference with late-payment interest, and a penalty file is possible when a base below the statutory one is declared. Which route suits a buyer depends on the strength of the file, and that is the next section.

The two routes to challenge it

Article 10 narrows the field: El valor de referencia solo se podrá impugnar cuando se recurra la liquidación que en su caso realice la Administración Tributaria o con ocasión de la solicitud de rectificación de la autoliquidación, the reference value can only be challenged by appealing the liquidation the administration issues, if it does, or on the occasion of a request to rectify the self-assessment. The Catastro repeats that La impugnación del valor de referencia sólo puede producirse cuando tenga efecto fiscal, y sea base imponible de los Impuestos sobre Transmisiones Patrimoniales y Actos Jurídicos Documentados o sobre Sucesiones y Donaciones, it can only be contested when it has a tax effect as the base of transfer tax or inheritance and gift tax. There is no abstract complaint against the figure on the e-office, and no tasación pericial contradictoria to start with. The resolution that sets the year's modules can itself be appealed within a month of its publication, but that is a challenge to the method for a whole territory, not to your flat.

Route one is the rectification: you filed on the reference value and ask the Agencia Tributaria Canaria to correct your own return and refund the excess with interest. Article 120.3 of the General Tax Act and articles 126 to 128 of Real Decreto 1065/2007 govern it. The request is made after filing and before the administration issues a final liquidation, within the four years in which the right to a refund lives; the office examines the file and may ask for more; El plazo máximo para notificar la resolución de este procedimiento será de seis meses, it has six months to notify its decision, after which silence counts as a refusal that opens the appeal. Route two is the appeal: you declared the price, the office liquidated the difference on the reference value, and you contest the liquidation, first before the office itself by recurso de reposición, for which El plazo para la interposición de este recurso será de un mes contado a partir del día siguiente al de la notificación del acto recurrible, the deadline is one month from the day after the notification, or directly before the Tribunal Económico-Administrativo Regional de Canarias within the same month. The TEAR charges no fees, and its decision opens the door of the Tribunal Superior de Justicia de Canarias.

Both routes meet the same gatekeeper. Article 10.4 says la Administración Tributaria resolverá previo informe preceptivo y vinculante de la Dirección General del Catastro, que ratifique o corrija el citado valor, a la vista de la documentación aportada, the tax administration decides after a mandatory and binding report from the Catastro that confirms or corrects the value in view of the documents filed, and the report must be reasoned: el valor de referencia ratificado o corregido será motivado mediante la expresión de la resolución de la que traiga causa, así como de los módulos de valor medio, factores de minoración y demás elementos precisos para su determinación, the confirmed or corrected value is reasoned by stating the resolution it comes from, the modules, the reduction factors and the other elements used. In the Tenerife case the Catastro's report cut its own figure from €309,631.27 to €302,211.81 and the agency refunded €441.01: the report corrected a datum and kept the method. Whether the tax office and the TEAR may stop there, with the Catastro's report in one hand and the buyer's appraisal unread in the other, is precisely what the Canary court refused and what the Supreme Court will now decide.

What the file should contain, from the cases that have been won and lost:

• The deed and the proof of payment. The price, the date, the Modelo 600 filed on the reference value and the receipt; the claim is for the difference and its interest.
• The Catastro's certificate of motivation. Obtained from the e-office after the deed; it names the module, the coefficients and the description the Catastro used, and it is the document your expert must answer.
• An appraisal of this property, not a mortgage valuation. Made by a registered valuer after visiting the inside, dated close to the deed, with the state of repair, the distribution and the defects recorded.
• Comparables identified one by one. The Tenerife appraisal named six sales in the same area; a list of asking prices from a portal is not evidence.
• More than one method. Comparison, cost and residual value converging on a similar figure is what persuaded the Canary court.
• An explanation of the discrepancy. The Burgos court rejected two files because the appraisal was handed in without a word on why the Catastro's figure exceeded the market; the gap itself proves nothing.
• The description errors, if any. Surface, year of construction, category or use wrongly recorded, with the plans or the licence that show it.
• Photographs dated at the deed. Of the interior above all; a later renovation makes a later visit worthless.
• The bank's appraisal, explained. It may support the file but cannot carry it; the courts have said so twice.
• The deadlines, written down. Four years for the rectification, one month for each appeal, six months for the office to answer; a late file loses with the best appraisal.

What the Constitutional Court said in February 2026

The question whether a base set by a mass-valuation formula respects the principle of economic capacity reached the Constitutional Court from Málaga. A buyer had paid €209,000 for a flat and a garage in Casares in June 2022 and filed at Andalusia's then rate of 7 %; the regional agency applied the reference value and liquidated the difference; the Tribunal Superior de Justicia de Andalucía referred articles 10 and 46 of the transfer-tax text and the third final provision of the cadastre act to the Court. Judgment 13/2026 of 12 February 2026, published in the BOE of 19 March 2026, upheld them. The Court found that nos hallamos ante un sistema de cuantificación objetiva de capacidades económicas potenciales que cuenta con una justificación razonable y suficiente desde el punto de vista constitucional, we are before a system of objective quantification of potential economic capacity with a reasonable and sufficient constitutional justification, and described the figure's place: el «valor de referencia» no es un medio de comprobación de valores sino el elemento definidor de la base imponible del impuesto, the reference value is not a means of checking values but the element that defines the base, so that the old check queda ahora reducida en su aplicación a los bienes inmuebles que, por sus características especiales, no tengan asignado un valor de referencia, is now confined to properties that, by their special characteristics, have no reference value.

The part that matters to a buyer is why the Court found the system acceptable: not because the figure is always right, but because it can be fought. It is, in the Court's words, una presunción iuris tantum en la determinación de un valor que exige una prueba suficiente en contrario para quien quiera desvirtuarla, a rebuttable presumption in the determination of a value, which demands sufficient proof to the contrary from whoever wants to displace it, and the Act creates un sistema abierto a su contradicción, que permite acreditar, sin límite probatorio de ninguna clase (dictámenes periciales incluidos) un valor distinto, a system open to contradiction that allows a different value to be proven with no limit of any kind on the evidence, expert reports included. The Court cited the Burgos court's judgment of February 2025 as an example of the ordinary courts applying exactly that. It ha decidido desestimar la presente cuestión de inconstitucionalidad, dismissed the question. The ruling settles that the floor stays; it also hands every buyer the argument that an appraisal must be read.

What the Supreme Court has yet to decide: a Tenerife case

The buyer whose clause we quoted bought a semi-detached house in Santa Cruz de Tenerife on 13 January 2022 for €259,900, with a bank appraisal of €255,419.33 and a reference value of €309,631.27. She filed on the price, then on the reference value, then asked for her money back. The Agencia Tributaria Canaria obtained the Catastro's binding report, which corrected the value to €302,211.81, and refunded €441.01; the TEAR dismissed her claim in August 2023. The Tribunal Superior de Justicia de Canarias, in judgment 358/2024 of 15 July 2024, gave her the whole refund with interest. Its reasoning is the one every later court has quoted: because article 10 allows the value to be challenged and requires the Catastro's report, no estemos ante una valor que goza de la presunción iure et de iure sino de una presunción iuris tantum, por ello susceptible de impugnación, we are not before a value with an absolute presumption but before a rebuttable one, open to challenge, and Difícilmente cabe su impugnación si con el informe emitido por la DGC y sin examinar el informe pericial de parte se desestima, sin más dicha impugnación, a challenge can hardly exist if it is dismissed on the Catastro's report alone, without examining the party's expert report. The court then read the appraisal, made for the mortgage but after an interior visit, found six identified comparables in the same area and three methods converging, and preferred it to the Catastro's module.

The Canary Government appealed. On 29 April 2026 the Supreme Court admitted the appeal, number 8442/2024, and fixed the question it will answer: Determinar si, en las transmisiones de bienes inmuebles, el valor de referencia fijado por la Dirección General del Catastro, to determine whether, in transfers of real estate, the reference value fixed by the Catastro es el que debe servir de base imponible en el Impuesto sobre Transmisiones Patrimoniales, en todo caso, must serve as the transfer-tax base in every case, or whether it is a rebuttable presumption that a court may set aside on other evidence, expert reports included, que permitan acreditar que el valor del bien es inferior al valor de referencia, proving that the property is worth less than the reference value. The order notes that no Supreme Court doctrine exists on the point and that the question affects a great number of situations. On 21 October 2026 no judgment had been published: the question is open. Until it is answered, the Canary court's position is the law applied on the islands, and the answer, when it comes, will bind the office, the TEAR and the court that decide the challenges filed today.

What the regional courts accept as proof, and what they reject

The Constitutional Court's no limit on evidence is not any evidence. The chamber the Constitutional Court itself cited, the Castilla y León court sitting in Burgos, has dismissed two challenges while agreeing with Tenerife on the principle. In judgment 32/2025 of 11 February 2025 it held that la mera diferencia de cuantías entre la tasación hipotecaria y el valor de referencia, sin explicación alguna que justifique la discrepancia y el error que se ha podido cometer en la valoración, o el por qué el valor de referencia es superior al de mercado, no sirve a los efectos de sustituir uno por otro, the mere difference between a mortgage appraisal and the reference value, with no explanation of the discrepancy, of the error that may have been made in the valuation or of why the reference value exceeds the market, does not serve to replace one with the other, while accepting that things are different where the appraisal is convenientemente explicada, por sí sola o conjuntamente con otros elementos probatorios, properly explained, alone or together with other evidence. In judgment 13/2026 of 2 February 2026 it dismissed again, because realmente se aporta una valoración alternativa, pero sin probar qué error puede tener el valor de referencia calculado por la Administración, what was filed was really an alternative valuation, without proving what error the administration's reference value might contain, and the comparables in the bank's report were not comparable.

Read together, the cases draw a line a Fuerteventura buyer can work with. A reference value will be displaced when the taxpayer shows either that the Catastro's description or computation is wrong, or that the market value of this specific property is lower, with an appraisal that visits, identifies, compares and explains. It will not be displaced by the price alone, by the bank's number alone, or by the general complaint that nobody visited: the Burgos court added that the administration cannot be asked to send an expert, because article 46 forbids the check when the base is the reference value. What is still unsettled is whether the tax office and the TEAR, and not only the court, must weigh the appraisal, and how far a judge may prefer it. That is the Supreme Court's pending question.

What our tax-law desk does

Our tax-law desk in Caleta de Fuste and Costa Calma takes over the conversation with the Canary tax agency the day the reference value becomes a problem. Before the deed, it pulls the certificate and, for an owner, the certificate of motivation, reads them against the property and tells the buyer what the base will be and whether the 5 % track survives. After the deed, it establishes what is actually open, files the rectification request with an appraisal built to the standard the courts have set, answers the Catastro's report, and appeals what is wrong: before the office, before the economic-administrative tribunal, where there are no court fees, and in court when it must go that far. Filing the Modelo 600 and the annual returns lives with our advisory desk; this one is for when the figure is challenged. Book a consultation and bring the deed, the Catastro's certificate and any appraisal you already have.

Common questions

Can I pay transfer tax on the price if the reference value is higher?

No. The base is the higher of the two, and a return filed on the price is corrected by a liquidation for the difference with late-payment interest, and may open a penalty file. If you believe the value is wrong, file on the reference value within the month, then ask for rectification and the refund of the excess with interest; the request can be made within four years, and the office has six months to answer.

How do I find the reference value of a flat I want to buy in Fuerteventura?

On the Catastro's e-office, with the data of a Spanish identity document, a digital certificate or Cl@ve, choosing the date of the planned deed; by phone through the Línea Directa del Catastro; or through the notary, who attaches the certificate to the deed. Ask for it before you negotiate, not after, and ask again if the signing moves into January, because the values change every 1 January.

Is the bank's appraisal enough to challenge the value?

On its own, no: the Burgos court dismissed two challenges built on a mortgage appraisal and the gap alone. The Canary court accepted an appraisal that had visited the interior, named six comparables in the same area, applied three methods and explained why the Catastro's module did not fit the house. The Supreme Court is now deciding whether courts may prefer such an appraisal in every case.

Does the reference value raise my IBI or my wealth tax?

Not your IBI: the Catastro states that the reference value does not affect the cadastral value in any way. Wealth tax values a property at the highest of its cadastral value, the value the administration determined for another tax and the acquisition price, so a reference value that served as the base of your purchase or inheritance tax enters that comparison, for properties acquired from 2022 onwards only.

Has the Constitutional Court settled the matter?

It settled that the floor is constitutional: judgment 13/2026 of 12 February 2026 dismissed the Andalusian court's question, because the value is capped at market level and can be rebutted with any evidence, expert reports included. What it did not settle is how the tax offices and the courts must treat that evidence, which the Supreme Court admitted for decision on 29 April 2026 in a Tenerife case and had not decided on 21 October 2026.

Facts verified in October 2026 (Real Decreto Legislativo 1/2004, third final provision and ninth transitional provision; Real Decreto Legislativo 1/1993, articles 10, 30, 46 and 49; Ley 29/1987, articles 9 and 18; Ley 19/1991, article 10; Ley 58/2003, articles 57, 66, 120, 223 and 235; Real Decreto 1065/2007, articles 126 to 128; Ley 20/1991, article 22; the Canary Decreto Legislativo 1/2009, articles 31 and 39, all in the text in force on 21 October 2026; Orden HFP/1104/2021; the Catastro's notices in the BOE of 8 October and 16 December 2025 and its questions and answers read on 21 October 2026; judgment 13/2026 of the Constitutional Court; the Supreme Court's order of 29 April 2026 in appeal 8442/2024 and its judgments 923/2026 and 1025/2026; judgment 358/2024 of the Tribunal Superior de Justicia de Canarias; judgments 32/2025 and 13/2026 of the Tribunal Superior de Justicia de Castilla y León). It is not advice for your case: the date of your deed, the Catastro's description of the property and the appraisal you can obtain decide what applies, and every route has a deadline of its own.