Víctor is a self-employed electrician in Toledo. He works mainly for a local construction company, which in 2025 paid him 38,000 € plus VAT, and for private customers. He did not file the Modelo 390 (the annual VAT summary) for 2024 or for 2025, because his previous adviser told him «that isn't paid». And the fourth-quarter 2025 Modelo 303 (the quarterly VAT return), with 2,300 € to pay, he filed on 30 January with an acknowledgement of debt (reconocimiento de deuda), because the construction company owed him two progress certificates (certificaciones). In June 2026 he received a letter from the Agencia Tributaria asking him for the 2024 annual summary. He asked us what happens if the 390 is not paid.
The answer has two parts, because in his case there are two separate problems that he saw as one.
The 390 is not paid, but it is owed
The annual VAT summary carries no tax. There is nothing to pay with it, and so there is no debt that can go into enforcement and no seizure that can arise from this Modelo. What there is, is an obligation to file it, and failing to do so has its own penalty: article 198 of the Ley General Tributaria (the General Tax Act) punishes not filing on time a return that causes no financial loss with a fixed fine of 200 €, halved if it is filed late without a request. These are the figures in the current text, which it is worth checking in its consolidated version.
Víctor already had a request (requerimiento) for 2024, so for that year he has lost the reduction: the fine would be the full one. For 2025, on the other hand, he could still file before being asked, and he did, in the same week he answered the 2024 request. And if a request is not answered, what gets added is another offence, that of not responding to the Administration, on top of the original one.
The unpaid 303 does follow the path of debts
The second problem was the one that cost money. The 2,300 € for the fourth quarter, filed without payment, entered the enforcement period (periodo ejecutivo) on 31 January 2026. From then on, the surcharge depends on when payment is made:
| Situation | Modelo | Consequence | Cost to Víctor |
|---|---|---|---|
| 2025 390 filed late without a request | 390 | Fixed fine halved | 100 € |
| 2024 390 filed after a request | 390 | Full fixed fine | 200 € |
| Q4 303 paid before the enforcement order (providencia de apremio) | 303 | 5 % enforcement surcharge | 115 € |
| Q4 303 paid within the enforcement order's period | 303 | 10 % reduced enforcement surcharge | 230 € |
| Q4 303 paid later, or by seizure | 303 | 20 % surcharge plus interest | 460 € + interest |
The two kinds of cost are not set side by side by chance: the 390 fines are fixed and do not grow with time, whereas the 303 surcharge moves up a band as soon as the enforcement order arrives. With limited money, the right order is to pay the 303 first and file the summaries afterwards, not the other way round.
VAT is a tax passed on to the customer, and as a general rule it cannot be deferred. The exception is precisely Víctor's: if it is shown that the VAT passed on has not been collected, that part can be deferred. The construction company's two progress certificates were the proof. With them in hand, what he had not collected could have been deferred in January, within the period, without a guarantee given its amount. We explain it in the debts that cannot be deferred.
If you have quarters filed and unpaid and annual summaries outstanding as well, tell us in the self-employed form: the urgent thing is to separate what generates a surcharge every week from what only generates a fixed fine.
Why the letter came: the cross-check almost nobody knows about
Víctor's construction company files Modelo 347 every year, the return of transactions with third parties, in which it reports every supplier it has paid more than 3,005.06 € in the year. Víctor appears on it, with 38,000 € plus VAT. The Agencia Tributaria cross-checks that information with what Víctor himself declares. Without an annual summary, the cross-check is made with the individual 303s, but the absence of the 390 is a signal in itself, and it was what triggered the letter.
The practical consequence is that the 390 fine is the least of it. What the request opens is the possibility of the Administration looking at the whole year: whether the bases on the 303s match what his clients declare, whether the deductible VAT has invoices behind it and whether there are transactions that were not declared. A self-employed person with everything in order comes out of that with a 200 € fine. One with discrepancies, with a limited VAT review. How to read the letter that arrives and what to answer is in what to answer and what not.
The certificate the construction company asks him for every year
There is one more consequence, and for Víctor it was the most urgent. Companies that subcontract works or services within their main activity can be liable for their subcontractors' debts for withholding and VAT passed on, unless they ask them for a specific certificate of being up to date with their tax obligations. That is why the construction company requires that certificate from him every twelve months, and without it holds back payments.
To obtain it, having no debts is not enough: you must have filed the returns you are obliged to file, and the regulations on tax management and inspection include among them, in their current wording, the annual VAT summary. In addition, a debt in the enforcement period that has not been deferred, such as the unpaid 303, also prevents it. Víctor had both obstacles at once. Until he filed both 390s and paid the 303, the Agencia Tributaria could not issue the certificate, and the construction company could not pay his progress certificates without taking on a risk. The circle closed on itself: he was not being paid because he did not have the certificate, and he was not paying because he was not being paid.
A Modelo having no tax does not make it optional. The 390 is the document with which the Administration closes your VAT year; without it, the year stays open to questions. And the fine, though small, is repeated for every year that is missing.
What Víctor did, and what he learned
- He paid the fourth-quarter 303 before the enforcement order was notified, with the 5 % surcharge: 115 €.
- He filed the 2024 390 in reply to the request, with the figures reconciled with his four quarters and with the construction company's 347.
- He filed the 2025 390 on his own initiative, before being asked.
- He reviewed his books for 2024 and 2025 to check that there were no differences other than timing ones between what he invoiced the construction company and what it declared.
The total cost was 415 € between surcharge and fines, plus the peace of mind of having closed two years that were open, and the certificate for the construction company, which he obtained as soon as the debt was paid and the summaries filed. What he learned is that in January two different things have to be filed, even though only one of them is paid, and that uncollected VAT can be deferred if you ask in time. The full mechanics of the quarters are in the guide to Modelo 303 for the self-employed.