Modelo 303: IVA. Autoliquidación

Who files it

Exceptions and special cases

All its deadlines

Each row is a deadline from the official calendar: the last day to file. When that day falls on a Saturday, Sunday or public holiday, the calendar already moves it to the next working day.

* Date worked out with the deadline rule, because the official calendar for that year has not been published yet. Check it when it comes out.

Every deadline of the year, month by month: 2026 tax calendar.

The same obligation with other tax authorities

What is declared here with form 303 goes on a different form, with different deadlines, at other tax authorities. Which one applies to you depends on where you are taxed, not on where you live.

Who would have it in their calendar

• Self-employed designer in Madrid: 5 deadlines in 2026.
• Plumber under modules in Zaragoza: 5 deadlines in 2026.
• Lawyer with an office in Valencia: 5 deadlines in 2026.
• Online shop with employees (S. L., limited company): 8 deadlines in 2026.

Official links

Where it is filed, its instructions and, if there is one, the file format for importing it. All on the website of the Agencia Tributaria (AEAT, the Spanish Tax Agency).

Frequently asked questions

Official sources

Where what this page says comes from, consulted on the review date. If something does not match, the source prevails.

1. 2026 tax calendar for Mainland Spain and the Balearic Islands Agencia Tributaria
2. Modelo 303 (trámite) Agencia Tributaria
3. Instrucciones 2026 Agencia Tributaria
4. Consultas informáticas - Modelo 303 (incluye importar fichero) Agencia Tributaria
5. Diseños de registro modelos 300-399 Agencia Tributaria
6. Diseño de registro 303, ejercicio 2026 y siguientes (xlsx) Agencia Tributaria
7. Pre303: formatos electrónicos de los libros registro de IVA e IRPF Agencia Tributaria
8. Pre303: diseños de registro normalizados de los libros registro Agencia Tributaria

Keep reading

• 2026 tax calendarThe 164 deadlines of 2026 in Mainland Spain and the Balearic Islands, month by month: the form, the period and the last day, copied from the official calendar. In .ics and .json.
• Filing lateWhat it costs to file a Hacienda form late or pay the Seguridad Social late: 1% per month, 15%, the €200 penalty and the 10% and 20% surcharges.
• Examples7 made-up profiles and the 2026 calendar that Mis Obligaciones’s rules give them: self-employed under direct assessment and under modules, companies, the Canary Islands, Bizkaia and Navarre.
• GlossaryWhat an autoliquidación, the 70% rule, REDEME, SII, IGIC, the Concierto Económico or RETA are, explained in two sentences with their official source.