AEAT Tax Request: What to Do (and What Not to Do) in the First 10 Days

Getting a request from the Spanish Tax Agency (AEAT) almost always triggers the same reaction: a spike of anxiety and the temptation to react on impulse — either ignoring it or scrambling to respond without a clear plan. Neither approach helps. In most cases, a tax request isn’t the start of an inspection with a guaranteed penalty; it’s a request for information or documentation as part of the routine control procedures AEAT runs at scale, especially when there’s a mismatch between what you’ve declared and what third parties — banks, clients, suppliers, Social Security — have reported. What separates a request that gets resolved smoothly from one that turns into a real problem is what you do in the first ten days.

What Types of Requests Can AEAT Send?

Not all requests are the same, and it’s worth identifying exactly which one you’ve received before taking action. The most common ones for freelancers and small businesses are the request for information or supporting documents (invoices, contracts, bank statements, or proof for a specific transaction), the request within a limited verification procedure (a procedure is already open for a given tax and fiscal year, and it usually ends with a proposed assessment), the summons to appear in person (asking you to show up at the tax office or bring documentation in person), and the generic request triggered by data-matching discrepancies — very common when an invoice reported by a client doesn’t match what the supplier declared, or when a bank deposit doesn’t square with declared revenue. The letter itself states, in its header and body, which procedure applies and what regulation backs it: that reference (concept, fiscal year, procedure) is the first piece of information to read carefully, not skim.

Deadlines: What to Do in the First Ten Days

Almost all requests are notified electronically, through the Dirección Electrónica Habilitada (the mandatory electronic address) or AEAT’s online portal, and the response deadline starts counting from the moment you access the notification — or from when the maximum access window expires, if you never open it. The typical deadline to respond to a request is ten business days, though each letter specifies its own exact deadline, and you should always go by the specific text you received, not a general rule of thumb. In those first few days, in this order: verify the request is genuine (through AEAT’s official online portal, never trusting links received by email or SMS, a channel heavily used for tax-related phishing); pin down exactly what’s being asked, for which fiscal year and which tax; gather the requested documentation — no more, no less; and file your response electronically before the deadline, keeping the confirmation receipt. Letting the deadline pass without responding or requesting an extension is the costliest mistake: it can lead to a penalty for failing to respond, on top of not stopping the procedure — which now continues with the tax authority in a stronger position.

Appeals and When to Call Your Advisor

If the request only asks for documents, and those documents back up what you declared, simply submitting them, properly labeled, is enough. Things change when the request includes a proposed tax assessment or an adjustment: that opens an appeals period, typically ten to fifteen days, during which you can challenge AEAT’s position with evidence and legal arguments before the proposal becomes a final assessment. Filing an appeal without solid grounds — or not filing one at all because you didn’t know you had that right — usually turns out to be expensive. As a rule, it’s worth calling your advisor as soon as the request arrives, not at the last minute: to confirm it’s genuine, to weigh whether to request an extension (possible in many procedures if you ask in time), and especially when the amount at stake is significant, when the request mentions a proposed assessment, or when it’s not clear exactly which documents cover what’s being asked. Ten days is plenty of time to do it right if you start on day one, not day nine.

At Zythos Business, we support freelancers and small businesses precisely through that first contact with the tax authority: we review the request as soon as it arrives, confirm its authenticity and scope, prepare the documentation the way AEAT expects, and, when needed, draft the appeal within the deadline. The difference between a request that’s resolved without consequences and one that ends in a penalty or assessment usually comes down to those first ten days — and that’s where an advisor makes the difference.