What Modelo 303 is and when it is filed

Modelo 303 is Spain's periodic VAT self-assessment return. Companies and self-employed workers use it to declare output VAT on sales and deductible input VAT on purchases and expenses.

Quick summary

• It declares VAT for a month or quarter.
• Most self-employed workers and small companies that file it do so quarterly.
• The calculation starts with output VAT and input VAT that meets the deduction requirements.
• The result may be payable, carried forward, refundable when permitted, or show no activity.
• A return may still be required when there are no invoices or no amount to pay.

Who files Modelo 303

As a general rule, it is filed by businesses and professionals that carry out activities subject to VAT and have a periodic self-assessment obligation. Specific regimes, activities, and territories can follow different rules.

Do not assume that you must file only because you issue invoices, or that you are exempt because there was no activity. Your tax registration, activity, VAT regime, and territory determine the specific obligation. Confirm it with your tax adviser.

How the general calculation works

The usual starting point is:

1. Add the output VAT on transactions in the period.
2. Identify input VAT that is deductible and correctly supported.
3. Include relevant corrections, amounts carried forward, and adjustments.
4. Calculate the result of the self-assessment.

Not all VAT on a purchase is deductible. How the expense relates to the activity, its supporting document, the timing of the deduction, and statutory restrictions can change the calculation.

You can use the free Numonis Modelo 303 calculator for an estimate. The calculator neither files the return nor replaces your adviser's review.

When it is filed

According to Spain's Tax Agency, quarterly self-assessments are generally filed:

• First quarter: April 1 to 20.
• Second quarter: July 1 to 20.
• Third quarter: October 1 to 20.
• Fourth quarter: January 1 to 30 of the following year.

Monthly self-assessments are normally filed from the 1st to the 30th of the following month. The January return may be filed through the last day of February.

The direct-debit deadline normally ends before the general filing deadline. Dates can also move when the last day is not a business day. Always check the current Spanish taxpayer calendar before filing.

What information you need to prepare

• Issued invoices, including corrective invoices.
• Received invoices and import documents where relevant.
• Taxable bases and VAT amounts separated by rate.
• Transaction date, invoice date, and recording period.
• Intra-EU transactions, exports, and other special transactions.
• Amounts carried forward from previous periods and relevant adjustments.

Reconciling invoices with bank transactions helps locate duplicates and missing documents, but a bank transaction does not replace an invoice by itself.

How Numonis helps

Numonis centralizes invoices, documents, and transactions so close is more organized. Upload documents throughout the period and respond to your adviser's tasks before the deadline. This gives your accountant time to review issues without concentrating all the work at quarter end.

See also what to upload and when and the monthly and quarterly close checklist.

Common preparation mistakes

• Including input VAT without a valid invoice or a sufficient connection to the activity.
• Recording an invoice twice or omitting a corrective invoice from the period.
• Confusing the payment date with the date that determines the VAT period.
• Missing intra-EU transactions, imports, or reverse-charge transactions.
• Waiting until the final day to locate missing records.

Frequently asked questions

Does Modelo 303 replace accounting?

No. It is a tax return. Accounting and invoice records are still necessary.

Can I prepare it only with receipts?

It depends on the expense, the information in the receipt, and the deduction you want to claim. Additional details may be required to deduct VAT from a simplified invoice, including the recipient's tax number and address and the VAT amount shown separately. Keep a complete invoice when required.

Must I file Modelo 303 if there was no activity?

You may still have to file a no-activity return. Do not omit it without checking your tax registration and periodic obligations.

Does a negative result mean the Tax Agency will refund the amount?

Not always. In many periods, the amount is carried forward. A refund depends on the period, applicable regime, and option available on the return.

Official sources

• 2026 Modelo 303 instructions
• Modelo 303 filing periods
• Invoice types and the requirements for deducting VAT

Notice

This content is informational and describes general rules. It does not replace personalized tax advice or confirm the obligations of a specific business.