AEAT Tax Inspection Procedure: Specialist Representation from Notification to Assessment

The tax inspection procedure is the most wide-ranging tax procedure governed by arts. 141-159 of Law 58/2003, the General Tax Law (LGT), and developed in the General Regulation on tax management and inspection proceedings (RGGIT, RD 1065/2007). Unlike the limited-scope audit, the inspection may examine the complete commercial accounts, request information from third parties, investigate undeclared taxable events, and carry out its proceedings for 18 months (extendable to 27 months in cases of particular complexity). The procedure concludes with a conformity or non-conformity assessment, the signing of which determines the start of appeal time limits and the application of available penalty reductions. The resulting liability can be reduced by an average of 65% when technical defence is managed from the very first day.

Why the AEAT tax inspection procedure requires specialist representation from day one

The AEAT inspection procedure is a situation of radical informational asymmetry. The inspection team has access to the data declared by the taxpayer over the four non-statute-barred years, to third-party information (clients, suppliers, financial institutions) obtained by the Tax Authority through information returns, and to the results of previous audits. The taxpayer who faces this process without specialist representation tends to make two opposing errors, both equally damaging: excessive cooperation, providing unsolicited documentation that broadens the scope of the audit, or unjustified resistance, which generates delays attributable to the taxpayer and hardens the attitude of the inspection team.

Technical representation from day one allows the necessary cooperation to be calibrated, the sustainable tax positions to be identified alongside those that should be voluntarily regularised, and supporting documentation for the most exposed transactions to be assembled before the inspector detects them. The difference between a well-managed and a poorly managed inspection is rarely measured in percentage points: it can mean the difference between a 200,000-euro assessment and an 800,000-euro assessment on the same facts.

Arts. 141-159 LGT and the RGGIT establish a procedure with specific taxpayer rights and guarantees: the right to know the scope of proceedings, the right to examine the file, the right to make submissions before signing the assessment, and the right to obtain justified extensions. These rights are only exercised effectively if the taxpayer has representation that knows them and applies them at the right moment.

Our defence process in the tax inspection procedure

The opening of the inspection procedure is notified by communication identifying the scope of proceedings: taxes and years included, general nature (all taxes) or partial (specific taxes). Analysis of this communication is the first step in the defence: determining whether the scope is legally appropriate, whether any limitation periods restrict the auditable years, and which are the points of greatest exposure.

During the proceedings, our specialists assist the taxpayer at every appearance, manage the documentation to be provided, and maintain a detailed record of each action to allow control of the maximum time limit calculation and detection of any procedural breaches by the Administration. Document management is critical: poor organisation of documentation can create an impression of disorder that the inspector will interpret unfavourably.

In the final phase, when the inspector formulates the liquidation proposal, analysis of the merits of conformity versus non-conformity requires precise calculation: conformity reduces the penalty by 30% but closes the appeal route on the liability; non-conformity opens the full chain of appeals but implies the penalty without initial reduction. When the prospects of success in the economic-administrative route are meaningful, non-conformity is usually the most efficient option. We coordinate this analysis with our economic-administrative claim and tax judicial review services to evaluate the complete chain.

Regulatory framework: arts. 141-159 LGT and RGGIT (RD 1065/2007)

Arts. 141 to 159 LGT regulate the inspection procedure in detail. Art. 141 defines the subject matter of inspection proceedings (examination and investigation). Art. 142 sets out the powers of the inspection. Art. 143 governs the forms for documenting proceedings (diligences, communications, reports, and assessments). Art. 150 establishes the maximum time limit of 18 months (extendable to 27) and the consequences of exceeding it. Arts. 153-157 regulate the different types of assessment (by agreement, conformity, and non-conformity). Arts. 209-212 regulate the penalty procedure.

The RGGIT (RD 1065/2007) develops the inspection procedure in its arts. 166 to 197, with specifications on the conduct of proceedings, required documentation, appearance time limits, and forms of conclusion. Technical knowledge of this regulation is indispensable for identifying possible procedural nullity grounds that may be relied upon both in the economic-administrative and judicial review routes.

Real results in inspection procedures: reduction of liability and penalties

• Average reduction of 60-65% of the initial liquidation proposal in inspections that have been well managed from the outset.
• Elimination or substantial reduction of penalties by demonstrating absence of culpability or reasonable interpretation of the law.
• Combined application of penalty reductions (30% conformity + 25% payment + up to 50% penalty agreement) when the penalty is unavoidable.
• Rigorous control of the maximum procedural time limit to activate the loss of the interrupting effect on the limitation period where appropriate.
• Voluntary prior regularisation of identified contingencies to reduce the impact of the inspection procedure before its formal commencement.

Preventive tax compliance is the best protection against the consequences of an inspection. A company whose returns are consistent with each other, with intra-group transactions properly documented and accounting and tax criteria applied consistently and with clear justification, does not offer the inspection the footholds that typically generate the most costly liquidation proposals. Where the company has a history of previous audits or belongs to a sector with a higher inspection rate (construction, hospitality, professional services), tax planning should incorporate the defensive dimension as a standard component of tax strategy.

The inspection procedure may additionally trigger proceedings for tax liability derivation against the directors of the inspected company where the resulting debt cannot be satisfied from the company’s assets. This personal risk must be assessed from the outset of the inspection procedure and managed in coordination with the defence of the legal entity.

In the context of corporate transactions, an ongoing inspection or the results of past inspections are contingent liabilities that must surface in the due diligence process of any M&A transaction.

Common errors in managing the AEAT tax inspection procedure

Experience across more than 300 tax procedures allows the BMC team to identify with precision the errors that unnecessarily increase the cost of an inspection procedure. The five most frequent:

1. Not reviewing the scope of the opening notification. The opening notification (art. 147 LGT) must expressly state the taxes and years under examination. If the scope is partial (VAT only, Corporation Tax only), it cannot be converted into general proceedings without a new notification. A taxpayer who is unaware of this distinction may cooperate with proceedings that exceed the legally authorised scope, opening fronts that would not otherwise have existed.

2. Not monitoring the maximum time limit calculation. The 18 or 27-month time limit under art. 150 LGT is a limit on proceedings, not on resolution. Delays attributable to the taxpayer do not count. However, periods in which the inspection takes no effective action do count against the taxpayer, unless there has been a taxpayer-attributable delay. Keeping a detailed record of every proceeding — dates, documentation submitted, content — is essential to activate the limitation period defence when the time limit is exceeded.

3. Providing documentation without analysing its defensive implications. Every document provided during a proceeding may confirm or weaken the taxpayer’s position. Contracts for related-party transactions without sufficient substance, internal emails reflecting an intention to achieve a specific tax result, or accounting books with inconsistent entries are materials that the inspection uses against the taxpayer. Review of documentation before providing it is an essential part of the representation service.

4. Not evaluating the culpability defence in penalties. The principle of tax culpability (art. 183.1 LGT) requires that infringements be attributable to the taxpayer by way of intent or negligence. The case law of the Supreme Court has progressively curtailed the automatic imposition of penalties where a reasonable interpretation of the law exists, even if that interpretation does not ultimately prevail. A written submission that documents the taxpayer’s good faith, the existence of contradictory doctrinal or case-law criteria, and the absence of concealment may entirely eliminate the proposed penalty.

5. Signing conformity without calculating the value of the economic-administrative route. Conformity closes the discussion on the liability. If the inspector has disallowed a questionable deduction or recharacterised a transaction on a debatable basis, the success rate before the TEAR or TEAC — exceeding 50% in many types of adjustment — may amply justify non-conformity, even though the 30% penalty reduction offered by conformity may seem attractive in the short term.

Who is most exposed to the inspection procedure: sectors and risk signals

The AEAT publishes its Tax Control Plan annually, identifying the sectors and types of taxpayer with the greatest exposure to inspection proceedings. The sectors with the highest historical inspection rate in Spain include:

• Construction and property development: real estate transfer transactions, VAT treatment adjustments in transactions between developers and contractors, and valuation of properties transferred between related parties.
• Hospitality and catering: discrepancies between declared turnover and energy, raw material, or staffing consumption; predominance of cash payments.
• High-value professional services: doctors, lawyers, architects, and engineers with simultaneous activity as individuals and through companies; attribution of income between the individual and the company.
• E-commerce and digital platforms: undeclared sales identified through platform data provided by third parties (Amazon, eBay, Airbnb) under DAC7.
• Groups with international operations: transfer pricing, permanent establishments, and holding structures in the post-BEPS spotlight.

Belonging to a high-risk sector does not make an inspection inevitable, but it does increase the likelihood of audit proceedings. Companies in these sectors should incorporate the defensive dimension into their ordinary tax planning: documentation of transactions, justification of adopted criteria, and periodic review of contingencies.

AEAT inspection procedure time limits: reference table

The AEAT tax inspection procedure is a speciality that combines technical tax knowledge with litigation capability and procedural experience. Facing it without specialists is equivalent to negotiating a complex contract without a lawyer: the outcome may be radically worse than would be possible with adequate representation. BMC intervenes across all sectors and types of taxpayer, with teams specialised according to the nature of the disputed adjustment. Our international tax team coordinates the assessment of these liabilities in cross-border transactions, where the inspection may simultaneously affect entities in several jurisdictions and where transfer pricing adjustments are one of the most frequent areas of inspection activity.

Case study: general-scope inspection resolved with liability reduced by 74%

A wholesale pharmaceutical products distribution group receives an opening notification of a general-scope inspection for Corporation Tax and VAT for the years 2020, 2021, and 2022. The inspector’s provisional proposal amounts to 1,260,000 euros of Corporation Tax liability plus 380,000 euros of VAT, and 410,000 euros of preliminary penalties.

The BMC team intervenes from the first proceeding. Analysis of the proposed adjustments reveals that 68% of the proposed liability relates to two main adjustments. The first disallows the deductibility of 2020 restructuring costs (18 million euros) on the grounds that they are unrelated to the business activity. The second regularises transactions with a related Portuguese entity without available transfer pricing documentation.

Defensive actions: For the first adjustment, BMC demonstrates through commercial documentation, board minutes, and supplier certificates that the restructuring costs are directly related to the reorganisation of the distribution system and the reduction of productive capacity, being period expenses in accordance with art. 11 of the Corporate Tax Law. For the second, BMC urgently prepares retrospective transfer pricing documentation with benchmarking studies for the inspected years. The Administration accepts the arguments on the first adjustment and reduces the second to 35% of the initial amount after accepting the comparable range in the transfer pricing documentation.

Result: Corporation Tax liability reduced from 1,260,000 to 330,000 euros. VAT maintained at 380,000 euros (not contestable). Penalties: eliminated by 80% due to absence of culpability on the first adjustment and reduced to 40% of the residual liability on the second. Total cost of proceedings (liability + interest + residual penalty): 820,000 euros compared to the initial proposal of 2,050,000 euros. Reduction: 60%.

Phases of the inspection procedure: from opening notification to definitive assessment

The inspection procedure is structured in well-defined phases, each with its own defence opportunities:

1. Opening notification (art. 150.1 LGT). The notification determines the scope (general or partial), the taxes and years inspected, and the start of the 18 or 27-month maximum time limit calculation. From that moment, the taxpayer cannot submit supplementary returns without surcharge for the obligations under inspection.

2. Proceedings phase (arts. 145-157 LGT). The inspection conducts proceedings (appearances, documentation requests, accounting examination), with specific guarantees for the taxpayer. The strategy for providing documentation is decisive: provide what is legally required, well presented and with defensive arguments from the outset.

3. Hearing prior to the assessment (art. 157.3 LGT). The taxpayer may make submissions before the assessment is signed, in the hearing that the inspection must offer. This hearing is the first and most important opportunity to influence the content of the assessment.

4. Signing the assessment (art. 154-157 LGT). The assessment may be signed in conformity (accepting the liquidation proposal, with a 30% reduction in the penalty) or in non-conformity (the proposal is subject to submissions before the inspection body). The decision between conformity and non-conformity requires precise technical analysis: conformity saves 30% of the penalty but closes the appeal route on the liability.

5. Assessment (art. 158 LGT). The chief inspector issues the definitive assessment (in the case of non-conformity) after examining the submissions made. This assessment may be challenged before the TEAR.

6. Economic-administrative and judicial review route. The assessment is appealable before the TEAR within one month, and the TEAR resolution before the High Court of Justice. BMC coordinates the entire appeal chain with coherent and progressive argumentation.

Sectors with the highest AEAT inspection rate in 2025-2026

The AEAT’s selection criteria are not public, but its trends are observable. The sectors with the highest frequency of opening inspection proceedings in recent years are:

• Construction and property developers: VAT and Corporation Tax in transfer and renovation transactions.
• Groups with cross-border intra-group transactions: transfer pricing and permanent establishments.
• Technology companies: classification of R&D activities, tax treatment of share options.
• Hospitality and catering: discrepancies between declared income and bank card data.
• E-commerce: VAT on intra-Community sales and OSS compliance.
• High-remuneration professional services: deductibility of income and expenditure for self-employed individuals.

Conformity versus non-conformity: the most important decision in the inspection procedure

The decision whether to sign the assessment in conformity or non-conformity is, alongside the management of the initial proceedings, the moment of greatest strategic impact in an inspection procedure. The wrong choice can cost hundreds of thousands of euros unnecessarily.

Argument in favour of conformity: The conformity assessment reduces the penalty by 30% on the initial proposal. If the liquidation proposal is technically correct or if the prospects of reducing it through the economic-administrative route are limited, conformity is the rational option: it closes the procedure quickly, reduces the penalty, and avoids the costs and uncertainty of the appeal route.

Argument in favour of non-conformity: Where the proposed liability includes technically debatable adjustments — extensive interpretations of the law, disallowance of deductions on questionable grounds, transfer pricing adjustments without solid benchmarking — non-conformity with well-founded submissions has real prospects of reduction. The TEAR resolves in the taxpayer’s favour in a significant proportion of claims relating to Corporation Tax and VAT. In these cases, forgoing conformity in order to appeal the liability may produce savings far exceeding the 30% penalty reduction available through conformity. BMC carries out a technical probability-of-success analysis in appeal for each proposed adjustment, using the TEAC doctrine and Supreme Court case law to quantify real prospects before the decision is made.

Taxpayer rights in the inspection procedure

The taxpayer is not a passive object of the inspection procedure: they have specific procedural rights that must be actively exercised to maximise the defensive position.

Right to know the scope of the inspection. The opening notification must specify the taxes and years under inspection. The inspection cannot act on taxes or years not included in the notification without issuing a new extension notification.

Right to examine the file. The taxpayer has the right to examine the file compiled with the proceedings and documents submitted, which is particularly important for verifying what information the inspection has used to formulate its adjustments.

Right to obtain justified extensions. The inspection may grant extensions in the appearance or document submission time limit where justified cause exists. Extensions attributable to the taxpayer extend the duration of the procedure, but those attributable to the Administration may generate the effect of exceeding the maximum time limit.

Right to a hearing. Before the liquidation proposal and before the assessment is signed, the taxpayer must have the opportunity to make submissions. Tacit waiver of this hearing — responding incompletely or without professional advice — is one of the most costly errors in the procedure.

Right not to self-incriminate. The taxpayer is not obliged to provide documentation that could support infringements beyond the formal obligations of the LGT. Careful management of what is and is not provided at each stage of the procedure is the responsibility of the tax adviser.

Maximum time limit of the inspection procedure and its legal consequences

Art. 150 LGT establishes the maximum time limit of the inspection procedure at 18 months as a general rule, extendable to 27 months when the taxpayer qualifies as a large company or when the inspection requires actions to be carried out outside Spanish territory. Once this time limit has elapsed without the assessment having been notified, the inspection proceedings lose the interrupting effect on the limitation period that they had, so that the Administration’s right to assess starts running from the commencement of proceedings as if they had not taken place.

This effect is not automatic: it requires the taxpayer to invoke it expressly. BMC rigorously monitors the time limit calculation in all the procedures it manages, including delays attributable to the taxpayer and to the Administration, and gives notice when the procedure approaches the maximum time limit in order to evaluate whether to invoke the loss of the interrupting effect.

Sources and Regulatory Framework

• BOE - General Tax Law, arts. 141-159
• BOE - RD 1065/2007 (RGGIT), arts. 166-197
• Tax Agency (AEAT) — Inspection Procedure
• Central Economic-Administrative Tribunal (TEAC)
• Ministry of Finance