The tasacion pericial contradictoria in Spain: challenging an AEAT property valuation under LGT Article 135

A taxpayer who receives an inflated tax valuation for a Spanish property transaction has a specific statutory weapon: the tasacion pericial contradictoria (contradictory expert valuation). It is the procedure in Article 135 of the Ley General Tributaria (Ley 58/2003) that lets you counter the value the tax administration has set through its comprobacion de valores powers, using your own independent perito’s figure. Filing the request suspends the liquidacion while the gap between the two valuations is measured, and if the gap is wide enough a perito tercero fixes the definitive number. This guide sets out how the procedure works, the thresholds that decide whether your valuation or a third perito’s prevails, who pays, and how the 2022 valor de referencia regime changed, but did not eliminate, its practical reach.

What is the tasacion pericial contradictoria?

The tasacion pericial contradictoria is the statutory correction mechanism in Article 135 of the Ley 58/2003 General Tributaria. It lets an interested party obtain a valuation “en correccion de los medios de comprobacion fiscal de valores” listed in Article 57 of the same law. In plain terms: when the administration has used one of its nine permitted means (capitalisation, reference to official fiscal registers such as the Catastro, market average prices, its own peritos’ reports, or others) to check a property’s value and has produced a figure higher than the one you declared, you can bring your own perito’s valuation to challenge it.

The procedure is available for any tax that uses comprobacion de valores: Impuesto sobre Transmisiones Patrimoniales (ITP, the transfer tax on resale property), Impuesto sobre Sucesiones y Donaciones (ISD, inheritance and gift tax), and other property-related levies. The Agencia Estatal de Administracion Tributaria (AEAT) publishes the procedure as GZ30 on its electronic sede, and the Junta de Andalucía’s own tax agency mirrors it for ceded taxes. The practical trigger is a liquidacion provisional, a tax assessment the administration issues when it believes your declared value was too low.

When can you request the tasacion pericial contradictoria?

Article 135.1 sets the window: within the deadline for the first recurso or reclamacion that is available against the liquidacion issued on the basis of the administratively checked value. That is typically one month from notification. The law also allows a reserva del derecho to promote the procedure, used when the notification does not express sufficient data and motives for the value increase. In that case you denounce the omission in a recurso de reposicion or reclamacion economico-administrativa, and the countdown starts from the date that resolution becomes final.

A critical protective effect: filing the solicitud, or reserving the right, suspends the ejecucion de la liquidacion and the deadline to appeal it. It also suspends the deadline to initiate any sanctioning procedure that might derive from the liquidacion. This means you are not forced to pay the disputed assessment while the valuation challenge runs, which can take several months. After the procedure ends, the administration issues a new liquidacion based on the resulting value and a fresh appeal period runs from that notification.

How does the valuation challenge work step by step?

The procedure, developed in Articles 161 and 162 of Real Decreto 1065/2007 and described on the AEAT’s GZ30 procedure page, runs in stages.

First, you file the solicitud. If the administration’s original comprobacion was not done with a dictamen de peritos of the administration, Article 135.2 requires the administration to produce its own perito’s valuation. The administration notifies you of that value and gives you 10 days to name your perito.

Once your perito is named, the administration delivers the list of bienes y derechos (the assets to value) to your perito, who has one month to produce the hoja de aprecio, the valuation report. If your perito fails to deliver within the month, the law treats this as desistimiento, the procedure ends and the administration’s value stands.

If both valuations are produced, the threshold test applies. If the difference, measured in absolute terms, is at most EUR 120,000 and at most 10 per cent of your perito’s figure, your figure becomes the tax base and the procedure ends. If the difference exceeds either threshold, a perito tercero must be appointed.

The perito tercero is chosen by public sorteo from lists that each administration requests annually (in January) from professional colegios, associations and corporations. If no relevant professional body exists for the asset type, the Banco de España designates a sociedad de tasacion from the official register. The perito tercero receives both prior valuations and has one month to either confirm one of them or produce a new valuation. The perito tercero’s valuation becomes the tax base, but Article 135.4 caps it within the range of the valor declarado (the original declared value) and the valor comprobado inicialmente (the administration’s first checked value).

What thresholds decide the outcome?

Threshold	Value	Effect
Small gap (Art 135.2)	Difference at most EUR 120,000 and at most 10 per cent of taxpayer’s perito figure	Taxpayer’s perito value becomes the tax base
Large gap (Art 135.2)	Difference exceeds EUR 120,000 or exceeds 10 per cent	Perito tercero appointed by sorteo
Cost allocation (Art 135.3)	Perito tercero value differs from declared value by more than 20 per cent (absolute)	Taxpayer pays perito tercero’s costs
Cost allocation (Art 135.3)	Perito tercero value differs from declared value by 20 per cent or less (absolute)	Administration pays perito tercero’s costs
Deposit default (Art 135.3)	Either party fails to deposit perito tercero’s honorarios within 10 days	That party accepts the other’s valuation regardless of the gap

The EUR 120,000 and 10 per cent test is conjunctive, not disjunctive: both conditions must be met for the small-gap rule to apply. If the gap is EUR 100,000 but that represents 15 per cent of your perito’s figure, the perito tercero is still required because the percentage threshold is breached even though the absolute threshold is not.

The 20 per cent cost rule creates a risk calculus. If your declared value was EUR 300,000 and the perito tercero lands at EUR 370,001, you pay the third perito’s fees. At EUR 360,000, the administration pays. This means a taxpayer who declared aggressively low bears a higher risk of the third perito’s costs, while one who declared close to market faces less cost risk.

Who pays the peritos?

The taxpayer always pays their own perito’s fees. The perito tercero’s costs are allocated by the 20 per cent rule above. The perito tercero can require a provision of honorarios by deposit at the Banco de Spain or the organism the administration determines, within 10 days, before starting work. If either party fails to make the deposit, that party is deemed to accept the other party’s valuation regardless of the difference. After the perito tercero delivers the valuation, the administration gives the taxpayer 15 days to justify payment of any honorarios due from the taxpayer.

The procedure can also end by desistimiento if the taxpayer fails to name a perito within the 10-day window, or fails to deliver the valuation within the one-month period, or if either party fails to deposit the perito tercero’s fees. In each of these cases the administration’s checked value stands and no new tasacion pericial contradictoria can be promoted for the same asset.

How did the valor de referencia change things?

The landscape shifted on 1 January 2022 when Ley 11/2021 introduced the valor de referencia de mercado (VRM), a value the Catastro publishes annually from real transaction prices reported by notaries. For ITP and ISD on most homes, the VRM became the default base imponible, replacing the older system where the administration had to run a comprobacion de valores to challenge a low declared value. The practical effect: if you self-assess (autoliquidacion) using the VRM and the administration does not perform a separate comprobacion, there is no administrative valuation to correct, and the tasacion pericial contradictoria does not trigger. The challenge route for the VRM itself is different: a rectificacion de autoliquidacion under Article 120.3 LGT, backed by a preceptivo y vinculante informe from the Catastro.

But the tasacion pericial contradictoria is not dead. The Tribunal Superior de Justicia de la Comunidad Valenciana, in its sentencia 580/2024 of 10 July 2024 (ECLI:ES:TSJCV:2024:3885), confirmed that when the administration does perform a comprobacion de valores, even one based on the Catastro’s valor de referencia under Article 57.1.b LGT, the taxpayer’s right to the tasacion pericial contradictoria under Article 135 remains available, and the solicitud or reserva suspends the liquidacion. The court reasoned that a comprobacion is a comprobacion regardless of the specific Article 57 means used, and Article 135 expressly covers all of them.

This means the procedure remains relevant in two scenarios: properties without an assigned VRM (commercial premises, offices, shopping centres, and transactions before 1 January 2022), and cases where the administration issues a liquidacion that performs an actual comprobacion rather than simply applying the VRM as the base. A separate constitutional question is open: the Tribunal Constitucional admitted a cuestion de inconstitucionalidad on 8 July 2025 regarding the VRM system itself, raised by the TSJ de Andalucía in Málaga, so the framework may yet move again.

How does this compare to other appeal routes?

The tasacion pericial contradictoria is one of several mechanisms, and choosing the right one matters.

A recurso de reposicion under Article 225 LGT is a general administrative appeal against the liquidacion, arguing procedural or legal error. It does not produce a new valuation; it asks the same administration to review its own act. A reclamacion economico-administrativa before the TEAR or TEAC is the next stage, an independent administrative tribunal. Neither of these replaces the tasacion pericial contradictoria, which is specifically a valuation correction tool, not a general appeal.

For IBI, the annual local property tax, the route is different entirely. IBI is based on the valor catastral, not on a comprobacion de valores, so the tasacion pericial contradictoria does not apply. The IBI challenge path is a rectificacion of the valor catastral through the Catastro’s own procedure, as explained in our guide to appealing property tax in Spain.

For mortgage valuations, the tasacion hipotecaria under Order ECO/805/2003 is a separate product altogether, as our property valuation guide explains. It is a bank-ordered valuation for lending purposes, not a tax challenge tool, and the two should not be confused.

What does this mean for a non-resident buyer?

A non-resident buying a resale property in Andalusia pays ITP at a flat 7 per cent, as our Andalusia transfer tax guide sets out. If the administration checks the value and finds it higher than declared, the difference is taxed at 7 per cent, plus demora interest. A EUR 50,000 upward adjustment means roughly EUR 3,500 in extra ITP. The tasacion pericial contradictoria lets you fight that adjustment with your own perito’s figure, and the suspension effect means you do not have to pay the disputed amount while the challenge runs.

For a non-resident seller, the 3 per cent retention on the declared price under Modelo 211, covered in our non-resident CGT guide, is calculated on the declared sale value, not on a comprobacion value. But if the administration later determines a higher acquisition value, it can affect the capital gain calculation, and the tasacion pericial contradictoria can be relevant to contesting that figure.

The key practical step is to commission an independent perito’s valuation early, ideally before filing the autoliquidacion, so that if a comprobacion arrives you can respond within the 10-day window. A perito arquitecto with experience in the local market, registered with the relevant colegio, produces the strongest hoja de aprecio. The perito’s report should be motivated, refer to the state of the property at the date of the hecho imponible, and use comparable transactions with proper homogenisation, as the procedural rules require.