What to Do When You Receive an AEAT Letter

The first few seconds after opening a letter from Hacienda are rarely calm. Your eye goes straight to the deadline, a tax period, an amount, or the word requerimiento. Then comes the dangerous impulse: answer immediately, forward a screenshot to somebody, or leave it untouched because it feels too serious to deal with alone.

Take a breath, but do not leave the document unattended. An AEAT letter can be a routine communication, a request for information, the start of a procedure, a proposed adjustment, a payment notice, or a decision. The heading alone does not settle the issue. What matters is the document’s procedure, the action it asks for, the period it concerns and the deadline written there.

If an AEAT letter has just arrived, do not begin by drafting a defense. First confirm that it is genuine in the AEAT electronic office or DEHu, save every attached file, and identify the exact procedure, taxpayer, reference and deadline. The AEAT provides access to notifications and communications through its electronic channels, and its response service is tied to the document’s secure verification code (CSV) and procedure. AEAT: electronic notification FAQs and AEAT: replying to a requirement explain those official routes.

This is a general guide for freelancers, company directors and finance staff in Spain. It does not decide how you should answer a particular file, calculate a penalty or replace advice based on the notice itself. If the letter refers to a proposed assessment, a sanction, inspection, collection action, appeal, a large amount, several tax periods, or facts you cannot verify quickly, get professional help before you submit a substantive response.

Start with the official document, not the email alert

An email or a mobile alert can tell you that something is waiting. It is not a substitute for the notification itself. The law says that a notification may be made through the authority’s electronic office, the Single Enabled Electronic Address (DEHu), or both, depending on the administration’s system. It also defines electronic appearance as access to the content by the person concerned or their properly identified representative. Article 43 of Law 39/2015 is the rule to check.

That distinction is more than technical. A forwarded PDF may omit annexes. An alert may not show the file reference. A person with a certificate may be viewing the wrong company. Go to the official AEAT channel, sign in with the correct identity or representation, and download the complete bundle yourself.

Save it in a folder that is separate from ordinary email. Keep the notification, every annex, any payment document, and the access acknowledgement or receipt. Use a clear name, such as 2026-07-20_AEAT_reference_XXXX_tax-period. You are not creating bureaucracy for its own sake. You are preserving the version of the file you actually received, which makes it far easier to explain the matter to a tax adviser, accountant or lawyer later.

Also verify the basic identifiers before you read the narrative section. Check the full name or company name, NIF, department issuing the document, file or reference number, tax and period, date made available, and any date by which the AEAT says you must act. If one of those details does not match your records, do not treat the letter as a generic request addressed to you just because it arrived in an inbox you monitor.

Separate the deadline to open a notice from the deadline to answer it

This is the point that causes the most avoidable harm. There may be more than one clock running, and they do different jobs.

For electronic notifications that are compulsory or voluntarily chosen, access to the document is the moment at which notification takes effect. If nobody accesses it, the law treats it as rejected after ten calendar days from the date it was made available. Article 43 of Law 39/2015 and the AEAT’s notification FAQ describe this rule. Ignoring a compulsory electronic notification does not pause the underlying procedure.

That ten-calendar-day rule is not a universal reply deadline. The time to provide documents, make representations, pay, appeal, correct something, or attend an appointment comes from the document and the procedure that it names. Do not say “I have ten days” until you know which ten days you mean.

For example, the General Regulation for tax management and inspection procedures says that an individual information request normally gives no fewer than ten days, counted from the day after notification, to provide the requested information. It also specifies that such a request must identify the person required to provide information, the period concerned and the facts to which the information relates. Article 55 of Royal Decree 1065/2007 is useful context, but it does not turn every AEAT document into that type of request.

Write down both dates where relevant: the electronic availability date and the response deadline stated in the document. If the notice uses business days, calendar days, months, or a date written in full, copy the wording exactly. Do not rely on a mental calculation when the deadline affects your tax position.

Work out what kind of document you have

People often call every official letter a “Hacienda fine.” That is understandable, but it makes careful reading harder. The label and the requested action should guide you.

A communication may give information or make you aware of a step. A notification formally places an administrative act or document at your disposal. A requirement may ask for records, explanations or supporting evidence. A proposed assessment may explain an adjustment the AEAT is considering. A notice opening a sanction procedure, a decision, a payment document and an appeal notice each have their own procedural consequences.

Do not assume that the word requerimiento proves that the AEAT has found an error or that an inspection has started. Spanish tax law allows the administration to request tax-relevant data, reports, background information and supporting documents. The regulation makes a further distinction: a request related to compliance with the recipient’s own tax obligations does not, by itself, mean that a verification or investigation procedure has begun. Article 93 of the General Tax Law and Article 55 of Royal Decree 1065/2007 set out that framework.

An information request connected with your own tax obligations does not automatically mean an inspection has begun. The decision to seek help should depend on the procedure, the issue, the evidence available and the deadline, rather than the word “Hacienda” on the heading.

Read the first page and every annex with a pen or a notes document open. Extract:

the exact title of the document and procedure;
the issuing body and file/reference number;
the taxpayer and NIF concerned;
each tax, form, period, transaction or invoice range mentioned;
what the AEAT says it needs from you;
the legal basis and the stated deadline;
the channel named for responding; and
whether the document refers to allegations, an appeal, payment, a hearing, an appointment or attached evidence.

If the paper says you may appeal or make allegations, do not assume those are interchangeable. The AEAT’s own response guidance tells users to review the notice because a particular document may point to a different route, such as complementary documentation or a procedure-specific response. AEAT response guidance makes that caution explicit.

Build the evidence before you write a word

The worst response is usually not an impolite one. It is a rushed one that gives a partial explanation, sends documents from the wrong period, or makes a claim that the records cannot support.

Make a working list with two columns. In the first, put each item AEAT asks for, in its wording. In the second, record what proves it, where the file is stored and whether it covers the requested period. Typical material can include invoices, ledgers, bank statements, contracts, payroll records, accounting exports, VAT books, correspondence, proof of payment or prior filings. The correct set depends on the procedure; do not upload a general archive simply because it exists.

Match dates carefully. A request about one VAT quarter may not be answered by an annual summary. An invoice can support a transaction but may not show when payment was made. A bank movement can show payment but may need the invoice or contract to explain its commercial purpose. If a document is not available, record why, what you have done to obtain it and when you expect to have it. That is better than inventing certainty.

A sound response has a short chain of evidence: one list of what AEAT asks for, one index of the documents supplied, a concise explanation where one is needed, and the filing receipt that proves what was submitted and when. The AEAT says its electronic response service lets you enter the file/reference and subject, attach files and submit the presentation; when submission succeeds, the system shows a registration receipt. AEAT response guidance describes the process.

In practice, an index can be simple: Document 1: invoice 2025-041, dated 15 April 2025, supporting item 2 of the request; Document 2: bank statement, page 3, showing payment on 30 April 2025. Do not add legal arguments just to make the answer look substantial. State what you are supplying, what it supports and any material limitation.

Use the route named in the notice

The AEAT has a service for replying to requirements or submitting documents linked to a received document. It uses the CSV on the notification, and the options shown can differ depending on whether the person acts as the interested party or as a representative. The AEAT says that a representative must access with electronic identification. AEAT response guidance also notes that the service may show procedure-specific options.

That does not mean the generic response service is always the right route. If the document directs you to a named tax form, a specific procedure, a hearing, a payment service or an appeal path, follow that instruction. Sending a document through the wrong channel can create a record without answering the action that was actually requested.

Before the final submission, check the attachment list one by one. Open the PDFs after you generate them. Confirm that scans are readable, names do not accidentally disclose unrelated personal data, and the documents are attached to the intended file. The AEAT’s current guidance says the service accepts files only in accepted formats and flags a 64 MB file limit for an individual upload. AEAT response guidance is the place to check before relying on a large upload.

Then save the registration receipt alongside the original notice and your submission index. The receipt is evidence of filing. It does not prove that the AEAT agrees with your explanation, and it does not cure a reply that was sent late or through the wrong procedure. It does, however, preserve a precise record of your action.

Can you ask for more time?

Sometimes the documents sit with a bank, customer, former accountant or supplier. Sometimes the notice covers several years and you need to understand it before you can respond responsibly. Do not assume that silence will buy time.

Under the general administrative procedure rules, the administration may grant an extension, either on its own initiative or at the request of the person concerned, unless a specific rule says otherwise. The extension cannot exceed half of the original time limit and must not harm third-party rights. Both the request and the decision must happen before the original deadline ends. Article 32 of Law 39/2015 sets those general conditions.

This is not a promise that an AEAT file will be extended. The document may have a specific regime, and a request made after expiry cannot extend a time limit that has already ended. If you need extra time, identify the applicable procedure, ask early through the appropriate channel and keep the proof of your request. Where the consequences are material, get advice before you decide that an extension is available.

Errors that make the situation worse

Panic usually creates procedural errors before it creates tax errors. Avoid these habits:

Replying from memory. Your tax return, accounting system and the letter may describe the same issue differently. Read the exact wording first.
Treating the email alert as the notification. Use the AEAT electronic office or DEHu to obtain the document, annexes and evidence of access.
Confusing the access window with the reply deadline. Ten calendar days can concern electronic access in the circumstances set by law; it is not a shortcut for calculating the response period.
Sending a partial explanation to “stop the clock.” A bare message may not meet the requirement and may commit you to an inaccurate factual account.
Uploading everything. A document dump without an index makes it harder to show what answers each item and can expose irrelevant personal or commercial information.
Using the wrong taxpayer or representation. Companies need to confirm the entity and NIF, especially where an adviser has access to several clients.
Failing to save the receipt. You need a record of the notification, the submission and the time of each action.
Assuming a request has no consequences because it looks routine. The General Tax Law treats incomplete, inaccurate or false replies to individual information requests as a tax infringement in the situations covered by the law. Article 199 of the General Tax Law is a reason to be accurate, not a reason to guess at sanctions from a generic guide.

When it is sensible to get professional help before replying

You do not need an adviser for every message from the AEAT. A simple request that you understand, with clear records and a manageable deadline, may be something you can organize and submit carefully. But there are moments when a second set of trained eyes can prevent an avoidable mistake.

Ask for help before filing if the notice opens an inspection or sanction procedure, proposes a tax assessment, questions deductions or declared income, requests records you do not have, covers multiple tax periods, includes a payment demand you cannot reconcile, or refers to allegations, appeals or a hearing. The same applies if the deadline is close enough that you would otherwise submit an unverified answer.

Bring the complete file, not a summary from memory: the notice, annexes, dates shown by the electronic office, earlier communications, relevant filings and the records you believe answer the request. Tell the adviser what has already been submitted and provide the receipt. That lets them assess the actual procedure instead of trying to reconstruct it from fragments.

This guide explains a careful first response, not the legal answer to a particular file. A deadline, an extension, an appeal and the documents that matter all depend on the notice and the procedure named in it; Law 39/2015 contains general rules that may be displaced by a specific procedure. If you need immediate support to review an AEAT letter before you respond, use TaxFactory’s urgent tax assistance route so the file can be assessed with the original documents in front of you.

A 30-minute first-response routine

If you have just received a notice and feel frozen, give the first half hour a narrow purpose. Do not attempt to solve the tax issue yet.

Log in to the AEAT electronic office or DEHu through the official route and confirm the taxpayer identity.
Download the document, annexes and access acknowledgement. Save them together.
Copy the reference, procedure, tax period, notification date and response deadline into one note.
Mark every requested document or action without interpreting it yet.
Check whether you have enough time and records to prepare an accurate answer.
If the notice is complex or time is tight, send the complete bundle to the professional who will help you, rather than a cropped screenshot.

That routine will not make the letter pleasant. It will keep fear from deciding the next step. Once the dates and document type are clear, you can choose a response that matches the procedure rather than reacting to the alarm in the heading.

Frequently asked questions

What should I do first when an AEAT letter arrives?

Verify it in the AEAT electronic office or DEHu, identify the taxpayer and file reference, download the document and annexes, and note the stated deadline before preparing a response.

Does an AEAT letter mean I am being investigated?

No. A communication or an information request can have different purposes. A request related to your own tax obligations does not, by itself, mean that an inspection or investigation has started; read the procedure and requested action in the document.

How long do I have to open an electronic AEAT notification?

Where electronic notification is compulsory or has been chosen by the recipient, it is treated as rejected after ten calendar days without access. This is different from the deadline to answer the document, which must be checked in the notification itself.

Can I ask AEAT for more time to reply?

In general administrative procedure, an extension may be granted if it is requested before the deadline, does not exceed half of the original period, and does not harm third-party rights, unless a specific rule says otherwise. Check the document and obtain advice before relying on an extension.

Should I send a quick reply so that AEAT knows I have seen the letter?

Do not send a speculative or partial reply simply to show that you saw it. Use the response route stated in the document, provide only accurate and relevant material, and keep the electronic filing receipt.