The right not to incriminate yourself in tax inspections

Updated on 27 September 2026. We have reviewed this article against the text of the Supreme Court judgment and the current General Taxation Act, which has not changed on this point. We have corrected how the case is described (the taxpayer did not refuse to hand over the invoices) and added the limits set by the Supreme Court and what to do if you are being inspected.

Spain's Supreme Court (Tribunal Supremo) has laid down doctrine on how the right not to incriminate yourself applies when the tax authorities (Hacienda) inspect you and then penalise you. It did so in judgment STS 1578/2025 of 4 December (cassation appeal 3664/2023) and in judgment STS 1605/2025 of 10 December (appeal 2592/2023), which repeats the same approach in another case about invoices. The issue was not new, but these judgments set out where your duty to cooperate with the Agencia Tributaria (Spanish Tax Agency, AEAT) ends and where your safeguards against a penalty begin. As of September 2026 we are not aware of any later Supreme Court case law departing from them.

The right not to incriminate yourself and the duty to cooperate

Article 24.2 of the Spanish Constitution recognises the right not to testify against oneself, not to confess guilt and to be presumed innocent. The European Convention on Human Rights does not mention it expressly, but the European Court of Human Rights treats it as a core part of the right to a fair trial under Article 6. The General Taxation Act (Ley General Tributaria, LGT) does not regulate it either, but the Supreme Court makes clear that it applies to tax penalties and protects both individuals and companies, although individuals more strongly.

The conflict arises because the LGT requires you to cooperate:

• Article 29.2.f) requires you to provide the books, records and documents you must keep and "any data, report, background information or supporting document relevant for tax purposes" that you are asked for.
• Article 142.3 requires you to attend to the tax inspectors and cooperate with them.
• Article 203 penalises resistance or refusal. If you are under inspection and carry on a business, failing to provide specific invoices or supporting documents is punished with €3,000 at the first request, €15,000 at the second and, at the third, a proportional fine of €20,000 to €600,000. If what you fail to provide is your accounting books, tax records, files or software, the fine is a straight 2% of turnover for the last financial year whose filing deadline has passed, with a minimum of €20,000 and a maximum of €600,000. In both cases the fine is halved if you comply before the penalty proceedings end or, if earlier, before the inspection's hearing stage ends (art. 203.6 LGT).

That threat of a fine is what the Supreme Court calls legal coercion, and it explains the whole debate.

Two procedures with different rules

1. The inspection. Here the right not to incriminate yourself does not apply: you must cooperate, and the tax authorities can use everything they obtain to regularise your position and assess the tax due.
2. The penalty proceedings. These are handled separately unless you waive this (art. 208.1 LGT), and here the right does apply. Article 210.2 LGT allows evidence from the inspection to be brought in, but the Supreme Court warns that doing so automatically, without checking whether any of it was obtained in breach of the right, may infringe the Constitution and the Convention.

That is why not all evidence that is valid for assessing tax is also valid for imposing a penalty.

What the Supreme Court decided

The case

The judgment of 4 December deals with an appeal by a partnership (sociedad civil, an unincorporated Spanish partnership) taxed under the flat-rate module system, whose VAT for 2006 to 2008 was inspected. It received several requests, with a warning of penalties, to provide its invoices and bank account balances, and it complied. The inspectors concluded that it was invoicing in its own name work actually done by a related company, since it had only one employee and lacked the material resources, and penalised it for issuing invoices with falsified data.

This is worth making clear, because it is often summarised wrongly: the taxpayer did not refuse to hand over the invoices. It handed them over and later argued that using them to penalise it breached its right. The Supreme Court dismissed the appeal because:

• Invoices are documents that the law requires you to issue and keep (today, Article 29.2.e) LGT and Articles 2 and 19 of the Invoicing Regulation approved by Royal Decree 1619/2012; at the time of the facts, Royal Decree 1496/2003 applied).
• The penalty was not based on the invoices alone, but on their mismatch with the partnership's economic and employment reality.
• There was no speculative investigation: the invoices were requested to check specific tax years.

The doctrine it lays down

• Self-incriminating documents or information that you provide under a warning of penalties during an inspection or any other tax application procedure, such as a limited check (comprobación limitada) or a data verification (verificación de datos), can only be used to penalise you if they exist independently of your will. The tax authorities must check whether any evidence breaches the right and, if so, cannot take it into account, nor any evidence derived from it.
• The right only applies in the penalty proceedings. It covers not answering questions from which the offence can be directly inferred and not providing documents whose existence depends on your will.

The Supreme Court adds an important nuance. A duty to provide documents only overrides the right when the law sets it out precisely, as with invoices or accounting records. With open-ended duties, such as providing "any data relevant for tax purposes", the tax authorities must give reasons for that relevance in each case and request specific, pre-existing documents whose existence they know of with reasonable certainty. Speculative investigations (fishing expeditions) are not allowed.

What the tax authorities can use to penalise you

What to do if you are being inspected

• Do not refuse to hand over invoices or accounts by invoking this right: it does not protect you and exposes you to the fines in Article 203 LGT.
• You may decline to provide documents not required by tax legislation and those you have already submitted and the inspecting authority already holds (art. 99.2 LGT).
• If you receive a generic request, ask in writing for it to specify what is being requested and why it is relevant for tax purposes.
• Prepare your explanations and written statements carefully: they will be used to regularise your position. It helps if the official record (diligencia) states that you are responding to a request carrying a warning of penalties.
• Think carefully before waiving separate handling of the penalty proceedings or signing an agreed assessment (acta con acuerdo), which implies that waiver. In an inspection, the waiver must be made in writing within the first six months, or earlier if the hearing stage ends first (art. 26 of the General Regulation on the Tax Penalty Regime).

If penalty proceedings are opened against you

• Deadlines. The tax authorities can only open them within six months of notifying the tax assessment; after that, they can no longer do so (art. 209.2 LGT). Once opened, the proceedings must be concluded within six months of notifying you that they have started, a period that is extended if any of the circumstances in art. 150.5 LGT arises in the underlying inspection. If that limit is exceeded, the proceedings lapse and no new ones can be opened (art. 211 LGT).
• Submissions. You have 15 days from the proposed penalty, which in the abbreviated procedure comes with the notice opening the proceedings (art. 210 LGT). Check what evidence comes from the inspection and ask for anything that depends on your will, and anything derived from it, to be excluded. In the Supreme Court case, the partnership made no submissions.
• Culpability. There is no offence without intent or negligence (art. 183 LGT), and no liability if you acted with due diligence, for example relying on a reasonable interpretation of the law (art. 179.2.d LGT).
• Reductions. For the offences in Articles 191 to 197 LGT (such as failing to pay tax due), the penalty is reduced by 30% if you accept the assessment and by 65% with an agreed assessment (art. 188.1 LGT). Except with an agreed assessment, any penalty (after any reduction for acceptance) is further reduced by 40% if you pay on time and appeal neither the assessment nor the penalty (art. 188.3 LGT). If you appeal only the penalty and not the regularisation, you keep the reduction for acceptance (art. 212.2 LGT) but lose the 40% (art. 188.3 LGT). Penalties arising from an agreed assessment cannot be challenged through administrative appeals, and if you take the regularisation or the penalty to court you lose the 65% (arts. 188.2.a and 212.2 LGT). An administrative appeal against any other penalty suspends its collection without a guarantee (art. 212.3 LGT).

Common mistakes

• Believing that this right prevents the tax authorities from assessing tax. It only limits the penalty.
• Not checking, in the penalty proceedings, what evidence comes from the inspection and how it was obtained.
• Confusing this with a tax crime (delito fiscal): different rules apply there (arts. 250 onwards LGT), and the Supreme Court leaves that scenario aside.

Frequently asked questions

Can I refuse to answer the inspector? During the inspection, in principle no: the Supreme Court considers that the right does not apply in that procedure, and a refusal can be penalised. The protection comes later: anything that incriminates you and depends on your will should not be used to penalise you.

Has the law changed in 2026? No. Articles 29, 203 and 208 to 212 LGT keep their wording. What is new is the Supreme Court's doctrine.

If you are being inspected or have been notified of penalty proceedings, it is worth reviewing as soon as possible what you have provided and on what terms, because the deadline for submissions is short. If you wish, you can book a consultation and we will go through your file with you.

Legislation and sources

• Spanish Constitution, Article 24
• Law 58/2003, General Taxation Act (consolidated text)
• Royal Decree 2063/2004, General Regulation on the Tax Penalty Regime (art. 26)
• Royal Decree 1619/2012, Invoicing Regulation (arts. 2 and 19)
• CENDOJ case-law search engine: STS 1578/2025 of 4 December (appeal 3664/2023) and STS 1605/2025 of 10 December (appeal 2592/2023)