Modelo 303 is the Spanish quarterly (or monthly) VAT self-assessment return filed by businesses to declare output VAT charged on sales, input VAT recoverable on purchases, and pay or claim the net difference. It is the central compliance document for VAT in Spain.
In practice
What Is Modelo 303?
Modelo 303 is the standardised self-assessment form used in Spain to declare and settle VAT (IVA) obligations. It is filed either quarterly (the default for most businesses) or monthly (for companies registered in the Monthly VAT Refund Register — REDEME — and for large companies under the SII system). The form is submitted electronically through the AEAT’s online portal (Sede Electrónica).
Filing Deadlines
| Period | Deadline |
|---|---|
| Q1 (January–March) | 20 April |
| Q2 (April–June) | 20 July |
| Q3 (July–September) | 20 October |
| Q4 (October–December) | 30 January (following year) |
Monthly filers follow the same pattern — 20th of the month following the period — except December, which is due on 30 January.
When the deadline falls on a weekend or public holiday, it moves to the next business day.
Structure of the Form
Modelo 303 has three main sections:
1. Accrued VAT (IVA devengado) — Output tax Here you declare all VAT charged on sales and services during the period, broken down by rate (21%, 10%, 4%) and any intra-EU acquisitions or imports on which you self-account.
2. Deductible VAT (IVA deducible) — Input tax Here you declare all VAT paid on purchases, expenses, and imports that is recoverable. Invoices must be valid (facturas completas) and the expense must relate to your taxable business activity.
3. Result Output tax minus input tax = amount to pay (to pay to the AEAT) or excess to carry forward (if input tax exceeds output tax). Carrying forward is the default; a refund can only be requested on the Q4 annual return — or at any time by companies registered in the REDEME.
The Annual Summary: Modelo 390
At the end of each year, businesses also file Modelo 390, which summarises all four quarterly Modelo 303 returns. This is an informative return only — no additional payment is made — but it must reconcile precisely with the four quarterly returns. Discrepancies between Modelo 303 returns and Modelo 390 are a known trigger for AEAT enquiries.
Common Errors That Trigger AEAT Attention
- Input tax on non-deductible expenses: Entertainment, certain vehicles, and expenses with no business purpose cannot be recovered.
- Incorrect invoices: Only full invoices (facturas completas) — not simplified invoices/tickets — support input tax recovery above EUR 400.
- Timing mismatches: Input tax must be claimed in the period the invoice is received, not when payment is made.
- Reverse charge errors: Intra-EU acquisitions and certain domestic reverse-charge transactions must be self-accounted — they are both output and input tax in the same return.
- Prorrata: Businesses with both taxable and VAT-exempt activities must apply the prorrata method and cannot recover 100% of input tax.
Modelo 303 and the SII System
Companies under the SII (Suministro Inmediato de Información) submit invoice data electronically within four business days of issue or receipt. For these companies, Modelo 303 is largely pre-populated by the AEAT based on submitted data, reducing manual work but requiring rigorous real-time record-keeping.
Penalties for Late or Incorrect Filing
Late filing attracts automatic surcharges: 1% per month up to 12 months late (5% from month 1 to 3, 10% from month 3 to 6, 15% from month 6 to 12), rising to a penalty of 20%–150% if the AEAT initiates proceedings first. Correct, timely filing is therefore critical.
How BMC Can Help
Our tax compliance team prepares and files Modelo 303 returns for companies of all sizes, including SII-obligated entities. We manage the complete quarterly cycle: invoice review, VAT ledger reconciliation, form preparation, and submission, with alerts well ahead of each deadline.