# Modelo 303 of Bizkaia: Autoliquidación del Impuesto sobre el Valor Añadido

> Form 303 (Autoliquidación del Impuesto sobre el Valor Añadido) is filed with the Hacienda Foral de Bizkaia (Bizkaia’s own tax authority). In 2026 it has 14 deadlines in the official calendar: the first falls due on 25 February 2026 and the last on 28 December 2026.

- Address: https://misobligaciones.com/en/modelos/bizkaia/303/
- Reviewed on: 2026-09-21
- Language: en

## In a nutshell

- **Filed with:** the Hacienda Foral de Bizkaia (Bizkaia’s own tax authority)
- **For those taxed in:** Bizkaia
- **How often:** trimestral o mensual
- **Deadlines in 2026:** 14, from 25 February 2026 to 28 December 2026
- **Official calendar consulted on:** [21 September 2026](https://www.bizkaia.eus/documents/d/guest/calendario-fiscal-2026)

## Who files it

*Text from the official source, in Spanish*

Sujetos pasivos en régimen general; mensual si el volumen de operaciones del año anterior superó 6.010.121,04 € o si están inscritos en el Registro de devolución mensual (RDM).

## Exceptions and special cases

*Text from the official source, in Spanish*

- No se presenta 303 del 4T (trimestrales) ni de diciembre (mensuales no RDM): el resultado va al 390.
- Los inscritos en el RDM sí presentan 303 de diciembre (1-31 de enero), que es la autoliquidación final.

## 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.

| Period | Last day | Day |
| --- | --- | --- |
| 1T 2026 (trimestral) | 27 April 2026 | Monday |
| 2T 2026 (trimestral) | 27 July 2026 | Monday |
| 3T 2026 (trimestral) | 26 October 2026 | Monday |
| Enero 2026 (mensual) | 25 February 2026 | Wednesday |
| Febrero 2026 (mensual) | 25 March 2026 | Wednesday |
| Marzo 2026 (mensual) | 27 April 2026 | Monday |
| Abril 2026 (mensual) | 25 May 2026 | Monday |
| Mayo 2026 (mensual) | 25 June 2026 | Thursday |
| Junio 2026 (mensual) | 27 July 2026 | Monday |
| Julio 2026 (mensual) | 25 September 2026 | Friday |
| Agosto 2026 (mensual) | 25 September 2026 | Friday |
| Septiembre 2026 (mensual) | 26 October 2026 | Monday |
| Octubre 2026 (mensual) | 25 November 2026 | Wednesday |
| Noviembre 2026 (mensual) | 28 December 2026 | Monday |
| Diciembre 2026 (solo RDM) | 1 February 2027 * | Monday |

> * 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: [the 2026 tax calendar for Bizkaia](https://misobligaciones.com/en/calendario-fiscal-2026/bizkaia/).

## 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.

| Tax authority | Form | What it is |
| --- | --- | --- |
| Mainland Spain and the Balearic Islands | [303](https://misobligaciones.com/en/modelos/303/) | IVA. Autoliquidación |
| Canary Islands | [420](https://misobligaciones.com/en/modelos/canarias/420/) | Impuesto General Indirecto Canario. Régimen general. Autoliquidación trimestral |
| Canary Islands | [417](https://misobligaciones.com/en/modelos/canarias/417/) | Suministro Inmediato de Información. Autoliquidación |
| Canary Islands | [421](https://misobligaciones.com/en/modelos/canarias/421/) | Régimen simplificado. Declaración-liquidación trimestral |
| Álava | [303](https://misobligaciones.com/en/modelos/alava/303/) | IVA. Autoliquidación |
| Gipuzkoa | [300](https://misobligaciones.com/en/modelos/gipuzkoa/300/) | Declaración-liquidación trimestral de IVA. Régimen General |
| Gipuzkoa | [320](https://misobligaciones.com/en/modelos/gipuzkoa/320/) | Declaración-liquidación mensual de IVA. Grandes empresas |
| Navarre | [F69](https://misobligaciones.com/en/modelos/navarra/f69/) | Declaración-liquidación trimestral del IVA (régimen general y simplificado) |
| Navarre | [F66](https://misobligaciones.com/en/modelos/navarra/f66/) | Declaración-liquidación mensual del IVA (grandes empresas y devolución mensual) |

## Who would have it in their calendar

- [Carpenter with a workshop in Bizkaia](https://misobligaciones.com/en/ejemplos/carpinteria-en-bizkaia/): 3 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 Hacienda Foral de Bizkaia (Bizkaia’s own tax authority).

| For | Official link |
| --- | --- |
| Instructions and help | [Preguntas frecuentes: quién presenta el 303 y plazos](https://www.bizkaia.eus/ogasuna/faq/faq_detalle.asp?Idioma=ca&idregistro=900002779) |
| File it | [Sede electrónica (catálogo de trámites → IVA)](https://www.ebizkaia.eus/es/inicio) |
| Instructions and help | [Calendario fiscal 2026 (PDF)](https://www.bizkaia.eus/documents/d/guest/calendario-fiscal-2026) |

## Frequently asked questions

### When is form 303 filed in 2026?

According to the official calendar of the Hacienda Foral de Bizkaia (Bizkaia’s own tax authority): Enero 2026 (mensual), by 25 February 2026; Febrero 2026 (mensual), by 25 March 2026; 1T 2026 (trimestral), by 27 April 2026; Marzo 2026 (mensual), by 27 April 2026; Abril 2026 (mensual), by 25 May 2026; Mayo 2026 (mensual), by 25 June 2026; 2T 2026 (trimestral), by 27 July 2026; Junio 2026 (mensual), by 27 July 2026; Julio 2026 (mensual), by 25 September 2026; Agosto 2026 (mensual), by 25 September 2026; 3T 2026 (trimestral), by 26 October 2026; Septiembre 2026 (mensual), by 26 October 2026; Octubre 2026 (mensual), by 25 November 2026; Noviembre 2026 (mensual), by 28 December 2026.

### Who has to file form 303?

According to the Hacienda Foral de Bizkaia (Bizkaia’s own tax authority): “Sujetos pasivos en régimen general; mensual si el volumen de operaciones del año anterior superó 6.010.121,04 € o si están inscritos en el Registro de devolución mensual (RDM).”

### What happens if I file form 303 late?

In Bizkaia surcharges and penalties are set by its own foral general tax regulation, not by the national law: check them on the website of the Hacienda Foral de Bizkaia (Bizkaia’s own tax authority) or with whoever advises you. The national rule, which gives you an idea, is in [the guide to missed deadlines](https://misobligaciones.com/en/fuera-de-plazo/).

### Does Mis Obligaciones file form 303 for me?

No. Mis Obligaciones suggests it in your calendar with the reason, takes you to its official page and reminds you a week before and the day before. The filing is done by you, or your gestoría (tax adviser’s office), on the website of the Hacienda Foral de Bizkaia (Bizkaia’s own tax authority).

> This is information copied from official sources to help you find your way, not tax advice: your case may have exceptions. Check it on the authority’s website or with whoever advises you.

## Official sources

- [2026 tax calendar for Bizkaia](https://www.bizkaia.eus/documents/d/guest/calendario-fiscal-2026) — Diputación Foral de Bizkaia
- [Preguntas frecuentes: quién presenta el 303 y plazos](https://www.bizkaia.eus/ogasuna/faq/faq_detalle.asp?Idioma=ca&idregistro=900002779) — Hacienda Foral de Bizkaia
- [Sede electrónica (catálogo de trámites → IVA)](https://www.ebizkaia.eus/es/inicio) — Hacienda Foral de Bizkaia
- [Calendario fiscal 2026 (PDF)](https://www.bizkaia.eus/documents/d/guest/calendario-fiscal-2026) — Hacienda Foral de Bizkaia