Tax Calendar
Form 303
Quarterly VAT self-assessment — the difference between VAT charged to clients and VAT paid to suppliers.
Informational content updated to 2026. Deadlines, amounts and percentages shown on this page may change due to regulatory updates. For your specific case, please consult with our certified professionals before taking action. Schedule free consultation →
What is Form 303?
Form 303 (Modelo 303) is the periodic self-assessment of VAT (Impuesto sobre el Valor Añadido — IVA). Through it, self-employed workers and companies settle with the Tax Agency (AEAT) the difference between output VAT (charged to clients) and input VAT (paid on purchases and deductible expenses).
If output VAT exceeds input VAT, the result is a payment to the Treasury. If input VAT is higher, the surplus can be carried forward to the next quarter or a refund can be requested in the last quarter of the year.
Filing is quarterly for most self-employed workers and SMEs. Large businesses with turnover above €6 million per year file Form 303 monthly.
Who must file?
- Self-employed workers and businesses carrying out economic activities subject to VAT.
- Individuals and companies that sell goods or provide services liable to VAT.
- Mandatory even when the result is zero or negative (credit to carry forward).
Exceptions and exemptions:
- Self-employed under the simplified VAT regime for certain activities.
- Farmers and livestock breeders under the Special Agricultural Regime (REAGP).
- Activities entirely exempt from VAT (certain medical, educational and financial services).
Filing deadlines
| Period | Deadline |
|---|---|
| Q4 (Oct–Dec) | By 30 January (Direct debit by 25 January) VAT refunds can only be requested in Q4 (or monthly under the special scheme). |
| Q1 (Jan–Mar) | By 30 April (Direct debit by 25 April) |
| Q2 (Apr–Jun) | By 20 July (Direct debit by 15 July) |
| Q3 (Jul–Sep) | By 20 October (Direct debit by 15 October) |
If the deadline falls on a Saturday, Sunday or national public holiday, it shifts to the next working day. Always verify exact dates at sede.agenciatributaria.gob.es.
How to file
- 1 Access the AEAT electronic office: sede.agenciatributaria.gob.es.
- 2 Log in with a digital certificate, Cl@ve permanente or Cl@ve PIN.
- 3 Select Form 303 and the period to declare.
- 4 Enter or import from your accounting software: taxable base and output VAT amounts, taxable base and deductible input VAT.
- 5 If the result is a payment, choose your payment method (direct debit, bank transfer or NRC code).
- 6 Submit the return and save the confirmation receipt (CSV or PDF).
Required documentation
- Sales invoices for the quarter with taxable base and VAT itemised.
- Purchase invoices with deductible input VAT.
- VAT sales ledger (output VAT).
- VAT purchase ledger (input VAT).
- Previous quarter Form 303 (for any credit carried forward).
Penalties for non-compliance
- Late filing without prior notice from AEAT: 5% surcharge if less than 3 months late; 10% between 3 and 6 months; 15% between 6 and 12 months; 20% plus late-payment interest beyond 12 months.
- After a formal AEAT demand: tax infringement with penalty of 50% (minor), 100% (serious) or 150% (very serious) of the amount due.
These penalties are indicative. Seek advice from your tax adviser if you miss a deadline.
Last reviewed: June 2026. Tax regulations change frequently — check our tax calendar or contact our professionals for advice tailored to your situation.
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