August 25 2026
A Spanish tax inspection is the procedure by which the Spanish Tax Agency (AEAT) checks whether you have met your tax obligations and, if not, regularises your position through an assessment. It only reaches tax years that are not time-barred: four years. It starts with a notice of commencement, or with the inspector turning up in person, and ends with an acta and its assessment. The maximum duration is 18 months, extended to 27 in the cases in article 150.1(b) of the General Tax Act. Overrunning does not void it, but the authority loses the interruption of the limitation period.
Spanish tax inspection: requirements, stages and deadlines
What is a Spanish tax inspection?
A Spanish tax inspection is the administrative procedure by which the tax authority checks and investigates whether a taxpayer has complied with their tax obligations and, where it finds non-compliance, regularises their position through one or more assessments. That is the definition in article 145 of Act 58/2003, of 17 December, the General Tax Act (Ley General Tributaria, LGT).
The statute distinguishes two activities that overlap in practice. Verification (comprobación) looks at what you declared: the acts, items and valuations stated in your returns. Investigation looks for what is missing: facts of tax relevance not declared, or declared incorrectly.
Do not confuse an inspection with a routine query from a management office: a letter asking you to support one box of your return does not mean you are under inspection.
Who can be inspected, and how far can the AEAT go?
Any taxpayer can be inspected, but not for any year and not to any extent. The time limit is the statute of limitations: four years for the authority to assess the debt. The substantive limit is set by the notice of commencement.
That scope is either general or partial. It is partial when it does not cover all the elements of the tax obligation for the period under review; general in every other case. The distinction matters, because it determines what can be reopened later.
The inspector’s powers are broad: main and auxiliary accounting records, invoices, correspondence of tax relevance, databases and computer files, plus entry onto land and premises.
One boundary is not crossed lightly. Entering a constitutionally protected home requires your consent or a judicial warrant, and the application must state the purpose, necessity and proportionality of the entry. The Supreme Court set the decisive criterion: the warrant must be connected to an inspection already opened and notified, and none may be granted on a speculative basis or because a company pays less tax than its sector average.
How does the procedure start?
An inspection begins either on the authority’s own initiative or at the taxpayer’s request. The usual route is the first: a notice requiring you to appear and produce documents. From the day after that notice you have a period of not less than 10 days.
It can also start unannounced, with the inspector attending your business, offices or warehouses, where notice would compromise the work.
A point that costs money and is usually discovered too late: returns filed after the inspection has begun, covering the obligations and periods under review, do not produce the effects of art. 27 LGT. They stop counting as voluntary disclosures and lose the reduced surcharges. The window to put things right yourself closes when the notice is served.
If the scope is partial and you would rather close the whole year, you can ask for the inspection to become general. The window is short: 15 days from the notice of commencement. The authority then has six months to widen the scope or open a general inspection.
The stages of the procedure, step by step
- Commencement. Service of the notice, stating the subject matter, the obligations and the periods covered. The maximum duration starts running here.
- Investigation. Appearances, information requests and examination of documents; the officials set the place, date and time. The work may take place at your tax domicile, the place of business, the authority’s offices, or by videoconference.
- Hearing. The full file is disclosed to you so that you can make submissions and produce evidence before the acta is signed. This is the point of no return for evidence: afterwards no further supporting documentation may be added unless you prove it could not have been produced earlier.
- Signature of the acta. The document recording the proposed adjustment, classified as con acuerdo (by agreement), de conformidad (agreed) or de disconformidad (contested).
- Assessment. The act that fixes the final amount and closes the procedure. It can be challenged by recurso de reposición or an economic-administrative claim, within one month.
How long does a Spanish tax inspection take?
Proceedings must conclude within 18 months as a general rule, or 27 where one of the three cases in art. 150.1(b) LGT applies. Time runs from service of the notice of commencement until service of the assessment, and it is a single period covering every obligation and period under review.
| Item | Rule in force |
| General period | 18 months |
| Extended period | 27 months where annual turnover triggers a statutory audit; where the taxpayer belongs to a tax consolidation group or to the special group regime under review; or where the inspection covers the Top-up Tax (Impuesto Complementario) |
| Days requested by the taxpayer | Up to 60 calendar days in total, in blocks of at least 7 calendar days, applied for before the hearing stage opens |
| Extension for late production | 3 months where documents are produced after the third request and at least 9 months into the procedure; 6 months where produced after the acta and further work is needed |
| Suspension | Referral to the Public Prosecutor, a court order to stay, a conflict before the Arbitration Boards, or referral to the advisory committee, among others |
The third ground for 27 months is new: added by the sixth final provision of Act 7/2024, of 20 December, with effect for tax periods beginning on or after 31 December 2023.
The 60 days are the most underused tool in the procedure. You apply to the acting office at least seven calendar days in advance, you must justify the circumstances, and a refusal cannot be appealed. They buy time to organise documents without a live request running, and they extend the maximum period rather than eating into it.
Actas: by agreement, agreed and contested
The acta is a proposal, not the assessment. Its class governs what happens next and, above all, how much of the penalty reduction you keep.
| Class of acta | When it applies | Penalty reduction |
| By agreement | Undefined legal concepts, appraisal of facts, or estimates and valuations that cannot be quantified with certainty. Requires a guarantee or deposit up front | 65 % |
| Agreed | You accept the proposed adjustment. If no decision is served within one month of the date of the acta, the assessment is deemed issued as proposed | 30 % |
| Contested | You do not sign or you reject the proposal. You have 15 days to make submissions to the assessing office | No agreement reduction |
A further 40 % reduction applies to what is left after the agreement reduction, provided the penalty is paid within the voluntary period of art. 62.2 LGT (or under a deferral secured by bank guarantee or surety insurance) and neither the assessment nor the penalty is appealed. Refusing to sign is not neutral: the acta is then processed as contested.
If the AEAT misses the deadline, is the inspection void?
No. Missing the deadline does not cause the procedure to lapse; it carries on to its conclusion. But it produces three effects that, argued properly, change the financial outcome:
- The limitation period is not treated as interrupted by the work carried out within the period that was missed. In long files, that can leave the oldest year time-barred.
- Payments made between commencement and the first action taken after the deadline was missed become voluntary for the purposes of art. 27 LGT.
- No late-payment interest is charged from the moment of the breach until the procedure ends.
Track the calendar from day one. The recurring mistakes are different: producing documents only at the third request, which triggers the three-month extension; signing an agreed acta without reading its legal reasoning; and letting the hearing stage pass without submissions.
Tax inspections of non-residents: what changes
If you do not live in Spain the procedure is the same, but the logistics and the service of documents are not. Non-residents must appoint a representative where the rules require it. The consolidated Non-Resident Income Tax Act (IRNR, Royal Legislative Decree 5/2004) sets out those cases in art. 10: operating through a permanent establishment; the cases in its arts. 24.2 and 38; an express request from the authority because of the amount or nature of the income; and ownership of assets in Spain by residents of territories with no effective exchange of information. The appointment must be notified within two months. Failing to do so is a serious tax infringement, fined 2,000 euros, rising to 6,000 in those territories.
Your Spanish tax domicile is set by art. 11 IRNR: the place of effective management where there is a permanent establishment; the representative’s address or, failing that, the location of the property, where the income is from real estate. That is where notices are served, and where most files go wrong: the taxpayer finds out once the deadline for submissions has expired.
A practical point that saves plane tickets: proceedings may be conducted by videoconference or equivalent digital systems, with secure document transmission. The authority decides, and the taxpayer must consent.
On real exposure, the guidelines of the 2026 Annual Tax and Customs Control Plan, approved by Resolution of 11 March 2026, cover asset analysis of individuals, tax residence controls and the use of automatic exchanges of financial account information (CRS), country-by-country reporting and the administrative cooperation directives (DAC). Check your calendar too: modelo 210 filing deadlines have changed for accruals from 2026 onwards (AEAT).
Frequently asked questions
How many years back can the Spanish tax authority go? Four years, the limitation period for the authority’s right to assess, running from the day after the filing deadline for the return. With two qualifications: limitation does not bar verification and investigation under art. 115, and the right to review carried-forward losses, credits and deductions runs for ten years.
Can I refuse to let an inspector into my home? Yes, where it is a constitutionally protected dwelling: the authority needs your consent or a judicial warrant, and the application must state purpose, necessity and proportionality. Entry onto land and business premises needs no warrant, but it does need an entry order from the administrative authority, unless you consent to the access.
What happens if I ignore the notice of commencement? The procedure continues without you. Non-appearance does not stop it, may amount to an infringement for obstruction, and makes it easier for the authority to use the indirect assessment method. You also lose control over the facts recorded in the acta.
Is signing an agreed acta always the cheapest option? Not always. It cuts the penalty by 30 %, plus 40 % more if you pay within the voluntary period and do not appeal, but you accept the facts in the acta. Where the dispute is about legal characterisation and there is favourable authority, contesting can work out better.
I am a non-resident and the notice went to my Spanish representative. Is that valid? Yes. If you were required to appoint a representative and did so, service at their address is fully effective. Hence the importance of keeping the appointment current and agreeing an immediate-alert protocol with them.
How much longer than 18 months can an inspection run? Up to 60 calendar days more if you request them, three or six months for late production of documents, plus however long the suspension grounds in art. 150.3 LGT last. Justified interruptions and delays not attributable to the authority no longer come off the clock.
Conclusion
An inspection has rules, and those rules protect the taxpayer too: a defined scope, a file that must be disclosed, a deadline with consequences if missed, and actas with very different financial effects. The gap between a well-run file and a badly run one is rarely about the substance. It is about the calendar and the moment evidence goes in.
If you have received notice of the commencement of an inspection, or if you reside outside Spain and have income or property here, we recommend contacting us before responding to the first request from the tax authorities. At Martínez-Cardós Abogados we have over 40 years of experience managing and handling tax inspections, ensuring that the Tax Administration acts within the limits of the law. We review the scope of the inspection, the calculation of applicable time limits, and the strategy for agreeing with or contesting its findings.