Form 303 (modelo 303) is Spain's VAT self-assessment. Every quarter you tell the Tax Agency how much VAT you charged on your invoices and how much you paid on your business expenses. If you charged more than you paid, you pay the difference. If you paid more, the difference stays in your favour.
Freelancers and companies file the same form, calculated the same way.
Who files it, and how often
It's for anyone whose VAT period is the calendar quarter, including businesses in the simplified VAT scheme. Some companies file monthly, but as a freelancer or small company you will almost certainly file quarterly.
Deadlines
From the AEAT's own calendar:
| Quarter | Filing window | If you pay by direct debit |
|---|---|---|
| Q1 (Jan–Mar) | 1–20 April | 1–15 April |
| Q2 (Apr–Jun) | 1–20 July | 1–15 July |
| Q3 (Jul–Sep) | 1–20 October | 1–15 October |
| Q4 (Oct–Dec) | 1–30 January | 1–25 January |
If the last day falls on a non-working day (Saturdays count as non-working), the deadline moves to the next working day and the direct-debit window stretches by the same number of days. That is why, in the 2026 calendar, direct debit for Q4 2025 ran until 27 January.
You file online, with a digital certificate, Cl@ve or eIDAS.
What goes into the calculation
Two piles of VAT:
- Output VAT (IVA devengado or repercutido): the VAT on your own invoices. Invoice €1,000 plus 21% and you owe €210.
- Input VAT (IVA deducible or soportado): the VAT you pay on business expenses, as long as you have an invoice in your name.
Spain's standard rate is 21%. There are also 10% and 4% rates for certain goods and services, and the form has a slot for each.
The boxes you will actually use
Form 303 has a lot of boxes. A freelancer or small company usually touches only a few:
| Boxes | What goes in |
|---|---|
| 01, 02, 03 | Base, rate and VAT charged at 4% |
| 04, 05, 06 | The same at 10% |
| 07, 08, 09 | The same at 21% |
| 28 to 39 | Bases and deductible input VAT, split between running expenses and capital goods |
| 46 | General-scheme result: output minus input VAT |
| 69 | Result after adjustments and amounts carried over from earlier quarters |
| 71 | Final result (69 − 70 + 109) |
| 72 | If the result is negative, the amount you carry forward |
If you neither charged nor paid any VAT in the quarter, you tick the "no activity" (sin actividad) box.
Step by step
- Gather the quarter's invoices, issued and received, with their base, rate and VAT.
- Add up the VAT on your invoices for each rate (21, 10, 4%).
- Add up the deductible VAT on your expenses. Only business expenses with an invoice. A plain till receipt isn't enough: a simplified invoice only lets you deduct VAT if it shows your tax ID (NIF), your address and the VAT amount separately. Ask the shop for it.
- Subtract input VAT from output VAT.
- Open the AEAT website (the Sede electrónica), load form 303 for the quarter and fill it in, or import a file if your software produces one.
- Decide what to do with the result. If you owe money, pay it or set up the direct debit. If it's negative, you offset it in the following quarters. As a general rule, a refund of the balance in your favour is claimed in the return for the last period of the year.
- Keep the receipt (justificante).
A worked quarter
Example with made-up figures, just to show the maths.
Laura is a freelance designer. In Q3:
- She invoices €9,000 at 21%. Output VAT: €1,890 (boxes 07, 08 and 09).
- Her expenses with invoices: €2,000 at 21% (€420 VAT) and €300 at 10% (€30 VAT). Input VAT: €450.
Result: 1,890 − 450 = €1,440 to pay, by 20 October. If she wants to pay by direct debit, she files by the 15th.
Had her expenses carried €2,100 of VAT instead, the result would be −€210. She wouldn't get that back in October: she would carry it into the next quarter.
Mistakes we see a lot
- Deducting VAT from a receipt without your NIF. It doesn't count. Ask for an invoice.
- Deducting VAT on personal spending. If it isn't for the business, it isn't deductible. For a passenger car you also use privately, the VAT Act presumes 50% business use.
- Leaving out an issued invoice. If it belongs to the quarter, its VAT goes on that 303, even if you haven't been paid yet. The exception is the special cash-accounting scheme (criterio de caja), which has its own rules.
- Not filing because "there was nothing". With no activity, you still file and tick "no activity".
- Spotting a mistake and leaving it. File a corrective return (autoliquidación rectificativa) for the same period.
How Factuly helps
Factuly works out your 303 from the invoices you issue and the expenses you enter or scan. It shows the boxes one by one and, when the deadline comes, walks you through the AEAT website: download the official file, sign in with Cl@ve, choose how to pay and keep the receipt. You get a reminder ten days before each deadline.
Factuly doesn't file anything on your behalf. You sign it on the AEAT website, or your accountant does. See how it works in Taxes and quarterly plan. If your expenses are a pile of receipts, Expenses and receipt scanning saves you the typing.
For which expenses let you deduct VAT and income tax, read our guide to deductible expenses for the self-employed.
