Purpose and the right form
Modelo 303 is the periodic VAT self-assessment. Your activity and VAT regime determine whether and how you file; not every autónomo has the same obligation. It does not replace income tax Modelo 130.
What to prepare
Prepare issued and received invoice records, VAT rates and amounts, deductible-VAT evidence, prior credits and relevant EU or international transactions. Check your census obligations and the correct reporting frequency.
Spanish fields to review
IVA devengado is output VAT; IVA deducible is deductible input VAT. A compensar, A devolver, Resultado cero and Sin actividad are different outcomes. No sales does not automatically mean no VAT activity if input VAT exists.
How to submit yourself
Open the official AEAT service below and select the correct year and period. Identify yourself using a method accepted by that service, or use an authorised representative. Complete the form, validate it, correct blocking errors and review warnings. Select the appropriate payment or result option. Finish the official signing and sending process yourself. Download the filed declaration and receipt with its verification code; a saved draft, preview or payment alone is not proof of filing. Filing is electronic. Individuals may use Cl@ve where eligible; companies and other specified taxpayers require an electronic certificate. Pre303 assistance does not remove your responsibility to review the figures.
Deadlines and payment
Quarterly returns generally run 1–20 April, July and October and 1–30 January for the fourth quarter. Monthly returns generally run to day 30 of the next month, with the January-period February exception. Check non-working days and earlier payment cutoffs.
Common mistakes and next steps
Refund eligibility depends on the period and registration status; do not select a refund automatically for every negative result. Review whether separate annual or EU reporting is required. Use the correct year’s amendment procedure for errors.