How to file Form 303 in Spain, step by step with an example

How to file Form 303, in short

This is how to file modelo 303 (Form 303), Spain's VAT return, all online: log in to the portal of the AEAT, Spain's tax agency, with Cl@ve or a certificate, enter your output and deductible VAT, check box 71 and submit it by the 20th of the month after the quarter ends. The fourth quarter of 2026 is due by 1 February 2027.

On Form 303 you add up the output VAT for the period, subtract the deductible VAT on your business expenses, and pay the difference, carry it forward or ask for it back. For an overview of the tax, see VAT for the self-employed; for what the form is and who files it, see Form 303 with Melso. Here we get practical, box by box.

Two key terms:

• Output VAT (IVA repercutido or devengado): the VAT you add to your invoices. You declare it in the period in which it becomes chargeable (generally, when you deliver the goods or provide the service), even if you have not been paid yet, except under the cash accounting scheme. See the AEAT on when to charge VAT.
• Input VAT (IVA soportado): the VAT your suppliers charge you. Only the part that meets the requirements of the VAT Law is deductible.

Before you start: what to have to hand

Who files it: anyone required to file periodic VAT returns, including those under the módulos scheme and even if they invoiced nothing in the quarter, because article 71 of the VAT Regulation requires them even with no output or deductible VAT. You do not file it if you only carry out transactions exempt under article 20 of the Law (doctors or psychologists, for example), nor does a retailer under the equivalence surcharge scheme for those sales; their intra-EU purchases go on Form 309.

The small business VAT exemption in Directive (EU) 2020/285 (a national threshold of up to €85,000) is not in the consolidated VAT Law as of 12 October 2026, so you still file Form 303.

Form 303 deadlines in 2026

Most self-employed people file by calendar quarter. Under article 71.3 of the Regulation, only these file monthly: businesses whose turnover exceeded €6,010,121.04 the year before, those on the monthly refund register (REDEME) and some special cases such as VAT groups.

These are the quarterly deadlines, with the last day if you choose direct debit, as set in the annex to Order EHA/1658/2009:

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Why 1 February and 27 January in 2027: the general Q4 deadline ends on 30 January, which in 2027 falls on a Saturday, a non-working day under article 30 of Law 39/2015. Filing moves to Monday 1 February, and article 3.2.b of Order EHA/1658/2009 extends the direct debit deadline (25 January in annex II) by the same two days, to Wednesday 27 January. In January 2026, when Q4 2025 was filed, filing did not move (30 January was a Friday), yet the AEAT's 2026 taxpayer calendar, covering returns filed in 2026, still set direct debit for that quarter from 1 to 27 January. Every date is in the 2026 tax calendar.

If you file monthly, the general rule is the 1st to the 30th of the following month, according to the Form 303 instructions for 2026. January has its own deadline, and dates move when they fall on a non-working day: in 2026, the January period was filed from 1 February to 2 March, and the April period by 1 June. With direct debit, the general rule is the 25th of the following month (annex II of Order EHA/1658/2009), but the AEAT calendar adjusts the deadline: 25 February for January, 27 April for March, 26 August for July, 27 October for September and 24 December for November 2026.

New in 2026: according to the AEAT's note, Order HAC/27/2026 adapts the form to a scheme for fuels held in warehouses other than customs warehouses. It first applies to the second quarter of 2026 (or February, if you file monthly), under its single final provision. If you do not deal in fuels, it does not affect you.

How to file Form 303 on the AEAT online portal, step by step

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Step 1. Open the right filing option

The Form 303 page offers three options:

• Ejercicio 2026. Presentación y servicio de ayuda Pre303: the one you will almost always use. It can preload data from your record books.
• Simulador 303: for running the numbers without filing.
• Ejercicios anteriores: for periods in 2025 or earlier.

Step 2. Identify yourself

Individuals can use Cl@ve, a digital certificate or their electronic ID (DNI electrónico) or eIDAS. Companies (SA and SL) and anyone who files monthly must use a digital certificate, according to the instructions for periods 2T to 4T. An authorised professional can also file it for you.

Step 3. Your details and the period

Choose the tax year (2026) and the period (1T, 2T, 3T or 4T, the form's labels for Q1 to Q4). Your personal details are prefilled. Where relevant, tick REDEME, exclusively simplified scheme or joint return, and corrective (rectificativa) if you are fixing a return.

Step 4. Output VAT for the period

Enter the VAT chargeable in the quarter, even if unpaid (except under cash accounting). Each rate goes on its own row, with the tax base, the rate and the VAT amount. In 2026 the VAT Law sets the standard rate at 21% (article 90), the reduced rate at 10% and the super-reduced rate at 4% (article 91):

The total of all output VAT is box 27. The IRPF (income tax) withholding your clients apply does not go here: it goes on Form 130 or in your annual income tax return (Form 100).

Step 5. Deductible VAT

The bases and amounts of deductible input VAT go in boxes 28 to 39, with current transactions (boxes 28 and 29 for domestic purchases) separate from capital goods. The total to deduct is box 45. Only VAT that meets the Law's requirements counts. Two of them:

• You have an invoice to back it up. Article 97 of the VAT Law requires an invoice. A full invoice in your name counts, and so does a simplified invoice if it shows your NIF, your address and the VAT amount separately. A receipt without those details does not.
• The expense is used for your business. Article 96 excludes some expenses and others have their own rules: the VAT on a car or a motorbike is presumed to be 50% business use (article 95.Tres).

Capital goods are tangible assets you use in your business for more than a year and whose purchase value is at least €3,005.06 (the 500,000 pesetas cited in article 108 of the VAT Law). The same article excludes spare parts, packaging and work clothing, among others.

Step 6. From the general scheme result to box 71

The form chains several boxes. The formulas come from the 2026 instructions:

1. Box 46, general scheme result: box 27 minus box 45.
2. Box 64, total of results: box 46 plus, where relevant, the simplified scheme boxes and other adjustments.
3. Box 65: enter 100%, which is the usual case. It only changes if you pay tax both to the central State and to the Basque Country or Navarre: then you enter the percentage of your turnover in the common territory, according to the AEAT's instructions.
4. Box 66, attributable to the State: the same as box 64 in the normal case.
5. Boxes 110, 78 and 87: the balance you are carrying forward, the part you apply now (as much as possible) and what is left for later (110 minus 78).
6. Box 69, result: 66 + 77 − 78 + 68 + 108.
7. Box 71, final result: 69 − 70 + 109.

The boxes in those formulas you will hardly ever use:

• Box 77: import VAT assessed by Customs that you have not yet paid there. It is added to the result and you pay it with Form 303. Only if you meet the requirements of article 74.1 of the Regulation (deferred import VAT).
• Box 68: annual adjustment, only in the last return of the year and if you also pay tax to the Basque Country or Navarre.
• Box 108: only in a corrective return because of a difference in administrative criteria, when the adjustment cannot be made in the other boxes of the form; it can be positive or negative.
• Boxes 70 and 109: only in corrective returns. Box 70 holds what was payable in the return you are correcting, and box 109 the refunds already agreed.

Typically, box 69 is 66 minus 78, and box 71 equals 69.

Step 7. Choose what to do with the result

On the Presentar declaración tab you indicate the type of result:

• To pay (a ingresar): box 71 is positive. You pay by direct debit with the IBAN of an account in your name, or choose another method the AEAT accepts, such as the reference number (NRC) your bank gives you.
• To carry forward (a compensar): box 71 is negative. You enter the amount in box 72 and use it in later returns, for four years. The instructions do not allow a result to carry forward if you have already applied an earlier balance in box 78.
• To refund (a devolver): only in the last period of the year, unless you are on the REDEME.
• No activity (sin actividad): when you have neither charged nor paid any VAT in the period.

Step 8. Sign, submit and keep the receipt

Check box 71 again. On filing, the AEAT gives you a receipt with a number and a secure verification code: keep it, as you need it to correct the return and as a reference for the annual summary on Form 390.

Full example: Laura, graphic designer, third quarter of 2026

An illustrative example with made-up figures. Laura is a self-employed graphic designer in Valencia. She works for companies, invoices everything at 21% and files quarterly. Between 1 July and 30 September 2026 she has these transactions:

Invoices issued: 6 invoices with a total tax base of €9,000, for services provided in the quarter. Output VAT: €9,000 × 21% = €1,890.

Invoices received, all in her name and for business use:

She also has receipts for meals with clients totalling €95, without her NIF or address: with no valid invoice, that VAT does not count. And she is carrying forward a balance of €320 from the first quarter, when she bought a graphics tablet and invoiced little.

This is her Form 303, box by box:

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The laptop's purchase value is under €3,005.06, so it goes with current expenses (boxes 28 and 29), not as a capital good. As box 66 exceeds the €320 pending, she applies all of it. Boxes 70 and 109 stay empty because this is her first return for the quarter; they are only filled in on a corrective return.

If she wants to pay by direct debit, she must file by 15 October 2026 at the latest. If she pays another way, such as an NRC from her bank, she has until 20 October.

Paying by direct debit

Direct debit is the easiest way to pay. Under Order EHA/1658/2009:

• The account must be yours. It must be held by the person who owes the tax and accept direct debits. According to the 2026 instructions, since 2024 accounts at non-collaborating banks in the SEPA area are also accepted.
• The deadline is shorter. For quarterly filers, until 15 April, July and October and, for the fourth quarter, until 27 January. For monthly filers, generally until the 25th, with the adjustments the AEAT publishes.
• You pay on the date of the charge: the day it is debited from your account.
• If the charge fails, you still owe the money, even if it is not your fault. If the conditions of article 6 are all met (direct debit set up on time, an account in your name, enough funds and an order not revoked), you will not be charged surcharges, late-payment interest or penalties for that failure, under article 38.3 of the General Collection Regulation.

How to correct a Form 303: supplementary and corrective returns

For periods from the third quarter of 2024 (or September 2024 if you file monthly), the old supplementary return (complementaria) is now a corrective return (autoliquidación rectificativa) within the form itself, whether you owe more or the correction is in your favour. Earlier periods use a supplementary return or a request for rectification. According to the AEAT, VAT charged in error and transactions under the special schemes in chapter XI of title IX of the Law require a request for rectification. In normal cases:

1. Open Form 303 for the same year and period and tick the corrective return box.
2. Enter the receipt number of the return you are correcting.
3. Choose at least one reason for the correction. For ordinary mistakes, the reason is Rectificaciones.
4. Fill in the whole return with the correct amounts, not just the difference. In the first corrective return, box 70 holds what was payable in the earlier return, and the form works out the difference in box 71.

If it is in your favour, you can ask for a refund of what you overpaid or, within the direct debit window, cancel or change the original direct debit. If the mistake is in an invoice you issued, first fix the invoice with a corrective invoice.

If you forgot to deduct an expense

No correction is needed. Article 99.Tres of the VAT Law lets you deduct input VAT in the period in which you paid it or in later periods, as long as four years have not passed since the right to deduct arose (normally, when the transaction became chargeable). Include that invoice in next quarter's Form 303.

If you are late

If you file late on your own initiative, without a prior request from Hacienda (the Spanish tax authorities), article 27 of the General Tax Law sets a surcharge on the amount payable: a fixed 1% plus another 1% for each full month of delay. After 12 months, the surcharge is 15% plus late-payment interest for the time after that. It is cut by 25% if you pay the debt and the surcharge on time (article 27.5). Once you have received a request there is no surcharge, but there may be a penalty (article 191). If the result is zero or to carry forward, article 198 sets a fine of €200, cut to €100 if you file without a prior request; it is not automatic and can be reduced further.

In Laura's example, the deadline ends on 20 October. If she filed on 25 November with no prior request, one full month would have passed (21 October to 20 November) plus a few days, not enough for a second full month. The surcharge would be 2% (the fixed 1% plus 1% for the full month): 2% of €1,059.70 = €21.19. The 25% reduction in article 27.5 applies to the surcharge, not the debt: 25% of €21.19 = €5.30. If you pay on time, the surcharge comes to €21.19 − €5.30 = €15.89, on top of the €1,059.70 of VAT.

To pay, to carry forward or to refund: what each result means

• To pay: box 71 is positive after subtracting deductible VAT and applying any balances and adjustments that apply.
• To carry forward: under article 99.Cinco of the VAT Law, you subtract the excess in later returns for four years from filing the return in which it arose.
• To refund: article 115 only allows it in the last period of the year, except on the REDEME.

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On top of the year's Forms 303, article 71.7 of the Regulation requires an annual summary return unless you are exempt. We explain it in Form 390.

Common mistakes when filing Form 303

• Not filing when you invoiced nothing. If you must file periodic returns, you file anyway, even as no activity.
• Deducting receipts without the details. Without a full or simplified invoice showing your NIF, your address and the VAT separately, there is no deduction.
• Including the IRPF withholding. It is not VAT and stays off Form 303.
• Forgetting the balance carried forward. If you do not apply it in boxes 110 and 78, you pay more than you need to.
• Asking for a refund in the first, second or third quarter. Unless you are on the REDEME, a negative balance in those periods is carried forward.
• Setting up direct debit on the 20th. It closes on the 15th (27 January for the fourth quarter). If you miss it, pay with an NRC.
• Filing a second normal return to fix a mistake. Since the third quarter of 2024, the normal route is a corrective return with the original's receipt number.

How Melso helps

Melso is your AI tax agent, with human professionals behind it. You send it invoices and receipts on WhatsApp, it organises your income and expenses, spots what is missing and keeps track of your tax calendar. When Form 303 is included for your activity and tax profile, Melso and its professionals prepare and review it, you approve the exact draft in the app and, with the necessary authorisation, the professional files the approved version with the AEAT and you keep the receipt. See Form 303 with Melso and the plans and pricing, then click Get started at melso.ai or Message us on WhatsApp.

This article is for information only and does not replace professional advice for your case. Last reviewed: 12 October 2026.