Before anything else: this guide is general information from a fellow expat, not tax or legal advice. Rules, forms and the layout of the official websites change, and your own situation matters. Use these checks to know what questions to ask, then take the answers to your gestor, asesor fiscal or lawyer.
Why should I check my own tax position if a gestor files for me?
Because in Spain the taxpayer is the one the Agencia Tributaria (AEAT) holds responsible. A gestor or adviser can prepare and submit your returns, but the obligation to file, the surcharge for filing late and any penalty are addressed to you, not to them. If something is missed, the letter has your name on it.
That is not a reason to distrust the person who files for you. It is a reason to spend a few minutes, a few times a year, looking at what the tax office itself has on record. Most problems do not come from bad work. They come from the gap between the person who does the filing and the person who receives the post, and from changes that everyone assumed someone else had made.
I am self-employed in Valencia and I use a gestoría I trust completely. When I finally sat down and ran the six checks below on my own account, I still found an activity code that was never added, a registered tax address that was not my home, a quarterly VAT return that did not exist, a penalty procedure I had never seen, and a VIES registration that did not match my invoices. Every one of them was fixable. Every one of them would have been cheaper to fix earlier. None of them would have surfaced if I had waited to be told.
How do I get into the Agencia Tributaria sede without getting lost?
Everything below lives on the AEAT's electronic office, the sede electrónica, at sede.agenciatributaria.gob.es. You need one of three ways to identify yourself: a digital certificate (the free FNMT certificate most autónomos already have), a Spanish electronic DNI, or Cl@ve, the government's PIN and mobile login.
Your personal starting point is "Mi área personal", linked at the top right of the sede. From there you reach "Mis datos censales", "Mis expedientes" and "Mis notificaciones", which together cover most of the checks in this guide.
The sede quirk that wastes the most time: clicking into an actual service usually opens it in a new browser window, so if nothing seems to happen, look for a second window or a blocked pop-up. And direct links to individual service pages often fail with a server error when you open them later. Do not rely on bookmarks. Start from the sede home page and click down through the menus each time; it is slower once and faster every time after.
Menu names below are the ones shown on the sede in October 2026. The AEAT reorganises the site every so often, so if a label has moved, search the sede for the service name in bold.
Check 1: What does the certificado de situación censal tell me?
The certificado de situación censal is the AEAT's official summary of who it thinks you are as a business. It is free, it downloads as a PDF in a minute, and it is valid for 12 months. Request it from the sede under Certificaciones > Censales, or from "Mis datos censales" in your personal area.
Read it line by line, because it shows things your own paperwork may not:
- Your registered activities (the IAE epígrafes). If you do something you are not registered for, the invoices for it do not match your census.
- The periodic returns you are obliged to file, and how often: for a typical autónomo that means the quarterly VAT return (modelo 303) and the income tax prepayment (modelo 130), plus any withholding returns (modelo 111, 115) and the EU sales summary (modelo 349).
- Your VAT regime, and whether you are in the Registro de Operadores Intracomunitarios (ROI), the register that lets you invoice EU businesses without VAT.
- Your domicilio fiscal, the registered tax address.
An activity code I had been told was added to my registration had never actually been added. On paper I was doing work my census said I did not do. The same certificate showed a registered tax address that was not my home. Neither showed up anywhere else I looked. Both are corrected with a census update (modelo 036), but only once someone knows they are wrong.
Check 2: How do I see which tax returns were actually filed?
Use the AEAT's list of declaraciones presentadas (returns filed), reached from your personal area. It lists every return submitted under your NIF, by model, period and year, with the exact date and time it was filed. If you only ever run one check on this page, run this one.
It catches two things nothing else catches: a return that went in late, and a return that never went in at all. Compare the list against the obligations on your situación censal. Every quarter should show a 303 and a 130 (if you are on the standard regimes), and every year the annual VAT summary (modelo 390) and your income tax return.
One quarterly VAT return simply did not exist. The deadline had passed months earlier and there was no record of it on the sede at all. I had assumed it was filed because every other quarter was. The list of returns filed is the only place that would have told me.
Why it matters to find it yourself: a return filed late on your own initiative, before the AEAT asks for it, normally costs a surcharge (recargo) of 1% plus 1% for each full month of delay, rising to 15% after twelve months, under article 27 of the Ley General Tributaria. Once the AEAT has asked for it first, you are into a penalty procedure instead, which is a different and usually more expensive conversation.
Check 3: Where does the tax office send my post?
In "Mis datos censales", confirm two things: that your domicilio fiscal is an address where you actually open the post, and whether you are signed up for electronic notifications.
These two settings decide where official letters go. If you are subscribed to electronic notifications, they land in your electronic mailbox and are treated as delivered whether or not you read them (see Check 4). If you are not subscribed, the AEAT sends them on paper to your registered tax address. If that address is your gestor's or lawyer's office, an old flat, or a coworking space, that is where your notices go.
I was not subscribed to electronic notifications, and my registered tax address was my representative's office. So official post went there, on paper, and it was up to someone else to notice it, scan it and pass it on. That chain has one weak link, and Check 4 is what happens when it breaks.
The address you print on your invoices, the address on your census and the place you actually live can all be different. Only the census one decides where the AEAT writes. Our autónomo guide covers that "three addresses" problem in more detail.
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Check 4: Do I have unread notifications or open files?
Open "Mis notificaciones" and "Mis expedientes" in your personal area. The first shows communications addressed to you; the second shows files in progress (expedientes en tramitación): checks, requests for information, refunds, and penalty procedures. Also check the government's general notifications inbox, DEHú (Dirección Electrónica Habilitada única), at dehu.redsara.es, which collects electronic notifications from many public bodies, not only the tax office.
The rule that makes this urgent: under article 43.2 of Ley 39/2015, an electronic notification counts as rejected, and therefore served, once ten calendar days pass after it was made available without you opening it. Deadlines to respond or appeal then start running as if you had read it. Not knowing is not a defence.
A penalty procedure had been opened against me, notified and decided, all without my ever seeing a single letter about it. The notices had gone on paper to the registered address in Check 3 and never reached me. By the time I found the file, the penalty had already been decided. I would rather have found it at the "opened" stage, when there was still time to respond.
Check 5: Am I really registered for EU business sales (VIES)?
If you invoice businesses in other EU countries and leave VAT off with a "reverse charge" note, you and your client both need to be in the EU's VAT information system, VIES. In Spain that comes from being in the ROI (see Check 1). Test it yourself on the European Commission's free lookup at ec.europa.eu/taxation_customs/vies: choose Spain, type your NIF, and check it comes back valid. Do the same for each EU client's number before you invoice them.
VIES returned my number as invalid, while my VAT returns were declaring reverse-charge sales to EU clients. The return and the register disagreed, and nothing in the filing process flagged it. Only a manual lookup did. If you sell to EU businesses, this is a two-minute check that protects every invoice you send.
Check 6: Does my Social Security base match what I actually earn?
Since the 2023 reform, what an autónomo pays to Social Security is meant to follow real net income through a table of brackets (tramos). In practice you pay a provisional amount through the year, based on the income you declared when you chose your base, and Social Security reconciles it the following year against what your tax return shows. That reconciliation is called the regularización.
Look at your current base in Import@ss, Social Security's personal portal (portal.seg-social.gob.es), and compare it with the bracket your real income puts you in.
My declared base sat far below what my real income required, for a full year. It did not update itself. It took a second follow-up to get written confirmation that my income put me in the top bracket, at roughly double what I was paying. The difference arrives later as a four-figure catch-up bill. I cover how that works, and how to avoid the surprise, in the autónomo guide.
When should I run each check?
Twice a year for the full set, plus a two-minute look after every quarterly deadline. The quarterly returns (modelo 303 and 130) are due in the first 20 days of April, July and October, and in the first 30 days of January for the fourth quarter.
| When | What to check | Time |
|---|---|---|
| A few days after 20 April, 20 July, 20 October and 30 January | Check 2 (was it filed?) and Check 4 (any notifications?) | 2 minutes |
| February, after the year-end returns | All six checks, including a fresh certificado de situación censal | 30 minutes |
| July, after the income tax return and Q2 | All six checks again | 30 minutes |
| Whenever your work, address or income changes | Checks 1, 3 and 6 | 10 minutes |
Put the dates in your own calendar. The point of the exercise is that it does not depend on anyone remembering to tell you.
What should I agree with whoever files for me?
None of this replaces a good adviser; it makes the relationship work better. Four things are worth agreeing at the start, in writing, with anyone who files or receives post on your behalf:
- Every filing receipt (justificante de presentación) is sent to you the day the return goes in, so your own records match the sede.
- Every notification that reaches them for you is forwarded the same day, with the date it arrived.
- Whose digital certificate files your returns. If they file with theirs, some files and notices attach to their account, not yours, and you may not be able to follow them on your own login.
- Your own reference numbers for any open file, so you can check or chase it yourself.
What should I do if a check turns something up?
- A missing return: get it filed as soon as possible, before the AEAT asks for it. The voluntary late-filing surcharge is almost always the cheaper path.
- Wrong census data (activity, address, VAT regime, ROI): ask for a census update on modelo 036 and then download a new certificado de situación censal to confirm it took.
- A notification you missed: note the date it was made available and the date it counts as served (ten calendar days later if electronic). That date starts the clock for any response or appeal, so take it to your adviser straight away.
- A penalty: do not just pay or ignore it before asking about your options. Appeals have short deadlines (typically one month), and some penalties are reduced if paid on time without appealing, so the choice matters.
- A Social Security base that is too low: raise it now rather than waiting for the regularización, and set money aside for the difference already built up.
If you are new to all of this and still at the registration stage, start with our guide to becoming autónomo in Spain. And if you are not yet settled in, the NIE and empadronamiento guides cover the paperwork that comes first.
Checking your tax position in Spain: FAQ
Why should I check my tax position if a gestor files for me?
Because the Agencia Tributaria holds the taxpayer responsible. The obligation to file, any late-filing surcharge and any penalty are addressed to you, not to the person who files for you. A few minutes on the sede a few times a year shows you what the tax office actually has on record.
What is the certificado de situación censal?
It is the Agencia Tributaria's free official summary of your business registration: your registered activities, the periodic returns you must file and how often, your VAT regime, whether you are in the register of intra-EU operators, and your registered tax address. You download it from the sede with a digital certificate, electronic DNI or Cl@ve, and it is valid for 12 months.
How do I check whether my quarterly VAT return was filed?
Log in to the Agencia Tributaria sede, open Mi área personal and look at the list of returns filed (declaraciones presentadas). It shows every return filed under your NIF by model, period and exact filing date. Compare it with the obligations on your certificado de situación censal: each quarter should normally show a modelo 303 and a modelo 130.
What happens if I file a tax return late in Spain?
If you file late on your own initiative, before the tax office asks, you normally pay a surcharge of 1% plus 1% for each full month of delay, rising to 15% after twelve months, under article 27 of the Ley General Tributaria. If the tax office asks first, it becomes a penalty procedure instead, which is usually more expensive.
When is an electronic notification from the tax office considered delivered?
When you open it, or once ten calendar days have passed since it was made available without you opening it, whichever comes first. Under article 43.2 of Ley 39/2015 it then counts as served and deadlines start running, so check your notifications folder on a schedule rather than waiting for an email alert.
Where does the tax office send my letters if I am not on electronic notifications?
On paper to your registered tax address (domicilio fiscal). If that address is your gestor's office, an old flat or a coworking space, that is where your official post goes. Check it in Mis datos censales on the sede.
How do I check if my VAT number is valid for EU sales?
Use the European Commission's free VIES lookup at ec.europa.eu/taxation_customs/vies, choose Spain and enter your NIF. If you invoice EU businesses without VAT under the reverse charge, it should show as valid. In Spain this depends on being in the Registro de Operadores Intracomunitarios, which you can see on your certificado de situación censal.
How often should an autónomo check their tax position?
A two-minute check after every quarterly deadline (20 April, 20 July, 20 October and 30 January) to confirm the returns were filed and no notifications arrived, plus a full check of all six items twice a year, for example in February and July.
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