Daniel is a self-employed carpenter in Burgos. In mid-January 2026 he had on his desk the Modelo 303 (the quarterly VAT return) for the fourth quarter of 2025, with 1,940 € to pay, and the year's Modelo 390. He called to ask something that seems simple: «Which of the two do I pay, and how? Because on the 390 I can't find where the NRC goes». He could not find it because it does not exist. And behind that question was a more serious one: two clients owed him invoices from November and he did not have the 1,940 €.
Where the year's money is: on the 303, not the 390
The 390 is a summary: it settles nothing, has no amount to pay and allows no method of payment. Everything the year produces to pay or to be refunded is decided on the quarterly 303s and, in particular, on the fourth-quarter one, which is the last of the year. Both are filed from 1 to 30 January, but the money only goes through the 303.
| Fourth-quarter result | What you do | Where | Date |
|---|---|---|---|
| To pay | Pay by direct debit, NRC or account charge | Q4 303 | Direct debit until 25 January; the rest until the 30th |
| To be refunded | Tick the refund option and give the account | Q4 303 | Until 30 January |
| To carry forward | Carry the balance forward to the following quarters | Q4 303 | Until 30 January |
| Any of the above | Summarise the year | 390 | Until 30 January, no payment |
The specific dates can move if the last day is a non-working day; the Agencia Tributaria publishes the taxpayer's calendar with the exact dates every year.
The ways to pay the 303, briefly
Direct debit is the most convenient: you give the account when filing and the charge is made on the last day of the period, but it is only accepted until the 25th. After that, you pay by account charge from the tax agency's own online office (sede electrónica), which generates the reference number on the spot, or with an NRC (the payment reference code) obtained beforehand through online banking, with the exact Modelo, period and amount. With any of the three, the receipt that counts is the filing receipt, with the NRC included. The full mechanics of the quarterly return are in the guide to Modelo 303 for the self-employed.
When clients have not paid: VAT can be deferred, but not always
This was Daniel's real problem. In the fourth quarter he had invoiced 22,000 € plus VAT, with 4,620 € of output VAT, and had 2,680 € of deductible input VAT. Result: 1,940 €. But two clients, with invoices of 5,000 € of base, had not yet paid him. The VAT on those invoices, 1,050 €, he had to pay over without having collected it.
VAT is a tax that is passed on to the customer, and article 65.2 of the Ley General Tributaria (the General Tax Act) declares that debts for taxes that must be passed on cannot be deferred, unless it is properly shown that the tax passed on has not actually been paid. Applied to Daniel's case:
- The part collected: 1,940 − 1,050 = 890 €. He did collect that VAT from his clients; he cannot defer it and must pay it on time.
- The part not collected: 1,050 €. He can apply to defer it, proving with the invoices and bank statements that those clients have not paid.
- As the deferred debt is far below 50,000 €, the application has been exempt from providing a guarantee since April 2023.
The application is filed within the filing period for the 303, together with the return, and it does not avoid the late-payment interest on the deferral. How to apply and what payment schedule is realistic is in how to apply for a deferral and in the debts that cannot be deferred, which explains the exception for uncollected VAT.
If your clients have gone months without paying and the VAT on those invoices is choking you, tell us in the self-employed form: besides a deferral, there may be other ways out depending on how long each invoice has been unpaid.
What almost nobody tells you: the VAT on invoices that are never collected
If one of Daniel's clients never pays, the Spanish VAT Act allows the taxable base of uncollectible invoices to be adjusted and the VAT paid over without being collected to be recovered. It is not automatic: there are time limits running from when the VAT became due, requirements about claiming from the debtor, and a notice to the Agencia Tributaria within a short period. If they are met, the adjustment is made with a corrective invoice (factura rectificativa) and reflected on the 303 for the corresponding period. If the time limit is missed, that VAT is lost.
The other thing almost nobody looks at in January is what to do with a balance in your favour. If the fourth quarter shows a refund, you have to choose between asking for the refund or carrying it forward to future quarters. The refund is paid by the Administration within a period the law sets at six months from the end of the filing period, and it can carry out checks before paying; if it takes longer, it owes interest. Carrying forward, on the other hand, involves no wait, but the right to carry forward expires four years after the filing of the return in which the balance arose. Leaving a balance dragging on for years unused is risking losing it.
If on the fourth-quarter 303 you ticked «to carry forward» when you wanted the refund, the 390 does not fix it: the annual summary merely reflects what you decided in the quarter. To change the option, you have to correct the 303, not the 390.
Three January stumbles with these two Modelos
Filing the 390 before the 303. Nothing prevents it, but if the fourth-quarter 303 then changes because a late invoice turns up, the annual summary already filed no longer reconciles and has to be replaced. The natural order is the reverse: first the quarter, with its payment or refund, and then the summary.
Setting up the direct debit on the 26th. Direct debit for the fourth-quarter 303 closes before the filing period does. Anyone who tries it late can only pay by NRC or account charge, and if there is no money in the account that day, they file with an acknowledgement of debt (reconocimiento de deuda) and move into the enforcement period when the filing period ends.
Confusing the year's result with the quarter's. The 390 shows the result for the whole year, 5,000 or 10,000 €, and some people think that is the amount to pay in January. It is not: the first three quarters were already paid at the time. In January only the fourth is paid.
Daniel's 390, in the end
With the 303 sorted out, the annual summary was filed on 29 January with the figures from the four quarters, with no payment attached. Daniel paid the 890 € on the 20th with an NRC, applied to defer the 1,050 € in three instalments, proving the two outstanding invoices, and when one of the clients paid him in March, he paid the deferral early. The other client has still not paid, and the deadline for recovering that VAT as uncollectible is being watched in the calendar.