Modelo 303: a practical guide to Spain’s VAT return

What Modelo 303 is and who generally files

The AEAT describes Modelo 303 as the VAT self-assessment return. Its 2026 instructions cover taxable persons whose settlement period is quarterly and those whose settlement period is monthly. Special regimes and individual circumstances can change how the form is completed.

Filing frequency and general deadlines

According to AEAT, quarterly returns are generally filed from day 1 to day 20 of April, July and October. The fourth quarter is generally filed from 1 to 30 January. Monthly returns are generally filed from day 1 to day 30 of the following month, with a special February limit for January. Non-working-day rules can move the deadline.

Information to prepare

Collect identification details, output VAT records, deductible input VAT records, prior compensation amounts and supporting invoices. Reconcile totals to books and check exceptional transactions before completing the return.

A review-first workflow

1. Confirm the period and filing frequency. 2. Reconcile issued and received invoices. 3. Classify VAT bases and rates. 4. Review deductible VAT and exceptions. 5. Reconcile the result and supporting records. 6. Use AEAT’s current filing service and retain evidence.

Common mistakes and Modelo 390

Common risks include missing invoices, incorrect periods or rates, unsupported deductions and unreconciled carried-forward balances. Modelo 390 is the annual VAT summary; some taxpayers are exempt, while others must file it. Confirm your status in current AEAT instructions rather than assuming the 303 replaces every annual obligation.

How filing is made

AEAT states that Modelo 303 is filed electronically. The identification method available depends on the taxpayer; the current AEAT filing page explains certificate, Cl@ve and eIDAS conditions.

Frequently asked questions