Before anything else, establish two dates
The first is the date of notification, which is not the date you read it. If you are registered for compulsory electronic notification, a letter placed in your electronic address is treated as delivered ten calendar days later whether or not anybody opened it. If it came by post, notification is the date of delivery or of the second failed attempt.
The second is the deadline to reply, which is normally ten working days from the day after notification. Working days exclude Saturdays, Sundays and public holidays, and Spanish public holidays are national, regional and municipal, so the same ten days are not the same calendar span in two provinces.
Write both dates at the top of the file. Every decision that follows depends on them.
Then work out what kind of letter it is
| What it says | What it means | How serious |
|---|---|---|
| A request for information or documents | They want a specific document or explanation. No assessment is proposed | Routine, but answer it. Silence is itself an infringement |
| Commencement of a limited review | A procedure has been opened over a defined tax and period, and it will end with a decision | Serious. What you say now is on the file for the rest of it |
| A proposed assessment with a hearing period | They have already calculated what they think you owe and are giving you the chance to object | Serious, and the window is short |
| Notice of a penalty procedure | A separate procedure about fault, running alongside the tax | Take advice before replying. The arguments are different |
| A demand for payment | Collection, not assessment. The debate about whether you owe it has moved elsewhere | Urgent for different reasons — deadlines here are about suspension |
The heading of the letter states which it is, along with the tax, the period and the scope. Read that paragraph twice. A reply that answers a different question from the one asked wastes the deadline and the credibility together.
The sequence
- Diarise the deadline the day the letter appears, counting working days and checking the local holiday calendar.
- Read the scope. A limited review is bounded: a stated tax, a stated period, stated items. Anything outside that boundary is not being asked about and should not be volunteered.
- Gather exactly what is requested. If they ask for the invoices behind a deduction, send those invoices. Not the bank statements, not the whole year's file, not a narrative of your affairs.
- Check your own position honestly first. If the request reveals a genuine error, the choice is between arguing and correcting, and that choice is best made before you have committed to a version of the facts in writing.
- If you need more time, ask for it at least three days before the deadline. An extension of up to half the original period can be requested once, and it is normally granted when asked for in time. Asked for on the last day, it is refused.
- Reply through the electronic office, in the procedure's own file, keeping the receipt. A reply sent by email to somebody's personal address does not exist.
- Answer even when the answer is partial. Producing what you have, explaining what you are still obtaining and giving a date is a co-operative reply. Producing nothing is not.
The instinct to demonstrate good faith by sending everything is the most costly reflex in this area. A limited review is limited by its stated scope; documents volunteered outside it can widen what is being looked at, and they cannot be withdrawn. Answer the question that was asked, completely and on time, and nothing else.
The things that make it worse
- Not replying at all. Failure to co-operate is itself sanctionable, and after three attempts at notification the procedure continues without you.
- Replying informally by telephone. Useful for clarifying what is meant; worthless as a reply. Only what goes into the file counts.
- Producing documents that contradict the return. If the numbers do not match, that has to be handled deliberately, with an explanation, not discovered by them in a spreadsheet you attached.
- Regularising mid-procedure and expecting a surcharge. Once a procedure has been opened for that tax and period, voluntary regularisation is no longer available for it: the gentle surcharge regime of article 27 gives way to penalties. Which is exactly why the time to file missing years is before a letter arrives.
- Treating a proposed assessment as final. It is a proposal. The hearing period exists so that you can dispute the facts and the figures, and doing so is often the last cheap opportunity in the whole sequence.
When to involve a lawyer rather than a bookkeeper
Three signals. If the letter mentions a penalty procedure, because that is about fault and intention rather than arithmetic. If it concerns tax residence, because those cases are decided on evidence built over years and an offhand sentence in a first reply can be quoted back at you for a decade. And if the sums are large enough that an appeal is realistic, because the appeal is built out of what was said at this stage.
For ordinary requests — an invoice missing, a figure that does not reconcile, a certificate of residence not on file — a properly prepared reply with the documents attached closes the matter, and for clients of ours that is part of the service.
If the letter is about years you know are missing
Then the sequence above still applies, but the strategy changes, and it is worth being clear-eyed. Coming forward before a letter arrives keeps you in surcharge territory: 1 % plus 1 % for each complete month, rising to 15 % plus interest after a year. After the letter, for that tax and period, it is penalties. That difference is the reason the catch-up pages on this site exist, and why they end by saying the same thing: do it before the letter. Send us the letter and its notification date through the contact form, and do it on the day it arrives rather than the day before the deadline.
Rafael in Munich: a letter read late and answered too fully
Rafael lives in Munich and lets a flat in Fuengirola. One Sunday, out of curiosity, he logs into the tax office's online portal and finds a request about his 2024 Modelo 210 asking for the invoices behind the costs he deducted. It had been made available three weeks earlier, so it counted as delivered after ten days and his time to reply had almost run out. In a hurry he sent everything he had: invoices, bank statements, rental contracts from 2022 and 2023, and an email explaining that "some years he did not file because he did not know". What had been at stake was the deduction of some costs in one year. What he opened was something else.
The contracts for years nobody had asked about, and the written admission of unfiled years, meant those years could no longer be regularised with a surcharge once the tax office acted on them.
When a representative receives the letter as well
If you have authorised a representative to receive notifications, the letter reaches them too, but the deadline runs just the same for you. Agree beforehand that they will tell you on the day it arrives.
Timing an extension request
More time can be requested once. The request has to be made at least three days before the deadline expires, and the extension cannot exceed half of the original period. Asked for on the last day, it is of no use.
If a penalty does follow
Not everything is lost. Agreeing to the assessment and paying promptly both reduce the amount, and what you give up in exchange for those reductions is explained in the penalty and its reductions.
Years the letter does not touch
For the tax and period named in the letter, the surcharge route has closed. For other periods it may still be open, because voluntary regularisation is lost only for what the procedure actually covers. What counts as a prior request and what does not is in what counts as a prior request, and sorting that out before you reply can save real money. With help, Rafael managed to keep the review limited to 2024, and filed the other years himself, with surcharges, before anybody asked for them.