Form 303: quarterly VAT explained plainly

Who files it

As a general rule, if your tax registration requires periodic VAT self-assessments, you must continue filing Form 303 while that obligation remains active. If there was no output or input VAT in the period, select “No activity”. Read the official 2026 Form 303 instructions.

Not every economic activity requires Form 303, and some schemes have their own rules: exempt activities, the equivalence surcharge, the simplified scheme, pro rata VAT, intra-EU transactions and SII. Check your tax-registration status if you are unsure.

Only VAT on expenses linked to the activity and supported by the correct documents is deductible. Payment alone is not enough: you need a valid invoice and must meet the applicable deduction limits.

Quarterly deadlines

• Q1: 1 to 20 April.
• Q2: 1 to 20 July.
• Q3: 1 to 20 October.
• Q4: 1 to 30 January of the following year.
• If the last day is not a business day, the deadline moves to the next business day. Direct-debit deadlines are earlier.

What to check before filing

Once you have completed these checks, open the 2026 Pre303 filing and assistance service. The Spanish Tax Agency will ask how you want to identify yourself.

• All sales and issued invoices are included in the correct period.
• Every expense has an invoice and is deductible.
• Intra-EU and reverse-charge transactions are classified correctly.
• The amount carried forward matches the previous return.
• Check whether Form 390 applies to you; not every taxpayer must file it.