Guides
Tax Modelos

Modelo 303: Quarterly VAT

Updated on
12 Oct 2025
5
min read

Modelo 303 is Spain's quarterly VAT (IVA) declaration form that basically all VAT-registered autónomos must file. This modelo calculates the difference between VAT you've collected from clients and VAT you've paid on business expenses, determining whether you owe money to or receive a refund from the tax authorities.

Filing Modelo 303 keeps you compliant with AEAT requirements and helps you maintain accurate financial records. Regular quarterly filings also prevent large surprise payments at year-end by spreading your VAT obligations across manageable periods.

When to file Modelo 303

Modelo 303 follows a strict quarterly schedule with these non-negotiable deadlines:

  • First quarter: April 20th
  • Second quarter: July 20th
  • Third quarter: October 20th
  • Fourth quarter: within the first 30 calendar days of January of the following year

Missing these deadlines triggers automatic penalties and interest charges. Even if you have no VAT activity in a quarter, you must still file a nil return by the deadline.

Who must file Modelo 303

You must file Modelo 303 if you're registered for VAT in Spain as an autónomo. This requirement applies regardless of your income level or business activity, as long as you're VAT-registered.

The only exception is if you operate under the special VAT regime (régimen especial del criterio de caja), where you may have different filing requirements. Most standard autónomos fall under the general VAT regime and must file quarterly.

Common mistakes to avoid

  • Mixing VAT-exempt and standard rate transactions: Keep clear records of which services carry VAT and which don't. Professional services typically carry 21% VAT, but some activities may be exempt.
  • Forgetting input VAT deductions: You can deduct VAT paid on legitimate business expenses. Keep all receipts and ensure expenses relate to your professional activity.
  • Incorrect VAT rates: Different goods and services carry different VAT rates (21%, 10% or 4%). Using the wrong rate creates discrepancies that trigger reviews.
  • Late filing penalties: File by the deadline even if you owe nothing. Late filing penalties start immediately and compound over time.
  • Incomplete expense documentation: AEAT requires proper invoices or receipts for VAT deductions. Bank statements alone won't support your claims during an audit.

In this guide

Facturaz One

Everything you need as autónomo in one place.
€44
Monthly + IVA