What is the model 303 and who must file it in 2026

# What is the model 303 and who must file it in 2026

The model 303 is the quarterly self-assessment of the Value Added Tax (VAT). All self-employed individuals who carry out taxable and non-exempt activities are required to file it, regardless of whether the result is to be paid, offset, or refunded.

Those who develop activities fully exempt from VAT (for example, certain health, educational, or financial services regulated in article 20 of Law 37/1992 on VAT) are not required to file it. If you have doubts about whether your activity is exempt, consult directly with the AEAT or review the corresponding IAE epigraph.

The model 303 is also relevant for self-employed individuals under the RETA by real income system, which has been in effect since 2023, because the taxable base declared in VAT is one of the indicators that the Social Security can cross-check to verify the coherence of the net income declared and the autonomous contribution 2026 that corresponds to pay.

Deadlines for filing the model 303 in 2026

The AEAT establishes four quarterly liquidation periods. The filing deadlines in 2026 are as follows:

• 1st quarter (January-March): from April 1 to April 20, 2026.
• 2nd quarter (April-June): from July 1 to July 20, 2026.
• 3rd quarter (July-September): from October 1 to October 20, 2026.
• 4th quarter (October-December): from January 1 to January 30, 2027.

When April 20 falls on a Saturday, Sunday, or national holiday, the deadline is extended to the next working day. If the result is to be paid and the payment is domiciled, the filing deadline ends on the 15th of the corresponding month (except for the fourth quarter).

Filing is done exclusively through the AEAT's electronic portal, using a digital certificate, electronic ID, or Cl@ve system.

How to complete the model 303: structure and key fields

The form is divided into several blocks. Below are the most relevant ones for a self-employed individual under the general regime:

Block of VAT accrued (sales)

• Field 01: taxable base of operations at the general rate (21 %).
• Field 02: VAT amount resulting at 21 %.
• Fields 03-06: bases and amounts at the reduced rate (10 %) and super-reduced rate (4 %).
• Field 25: total VAT accrued (sum of all sales amounts).

Block of deductible VAT (purchases and expenses)

• Field 28: taxable base of current purchases with right to deduction.
• Field 29: VAT amount supported and deductible in current operations.
• Field 44: total deductible VAT.

Result of the assessment

• Field 46: difference between accrued and deductible VAT. If positive, the result is to be paid. If negative, it can be offset in subsequent quarters or, in the fourth quarter, request a refund.

It is essential that the invoices supporting the VAT supported are correctly issued in the self-employed individual's name with their NIF, since the AEAT may reject deductions without valid documentation.

Deductible expenses in VAT: what you can include in the model 303

One of the most common errors is confusing the deductible expenses in IRPF with those deductible in VAT. In the model 303, only the VAT supported on expenses related to the economic activity and supported by a complete invoice (not a receipt) can be deducted.

Among the most common deductible expenses for self-employed individuals that generate deductible VAT are:

• Workplace supplies (electricity, water, internet) if there is justified exclusive or partial allocation.
• Office supplies and computer equipment.
• Management, advisory, and publicity services.
• Business premises rental (if the landlord charges VAT).
• Vehicle: the VAT deduction is generally limited to 50 %, except if exclusive use for the activity is proven (article 95 of the VAT Law).
• Training expenses directly related to the activity.

Home expenses for self-employed individuals working from home have a specific and limited treatment; it is advisable to review the AEAT criteria and the jurisprudence of the TEAC before including them.

Practical example: calculation of the model 303 for a self-employed individual in the second quarter of 2026

Imagine a self-employed individual providing consultancy services (general rate of 21 %) with the following data for the second quarter of 2026:

Incomes (VAT charged):

• Gross billing: 12.000 € (taxable base)
• VAT charged at 21 %: 2.520 €

Expenses with deductible VAT supported:

• Software and licenses: base 400 €, VAT 84 €
• Online advertising: base 600 €, VAT 126 €
• Tax advisory: base 300 €, VAT 63 €
• Office supplies: base 150 €, VAT 31.50 €
• Total deductible VAT supported: 304.50 €

Result of the assessment:

• VAT accrued (field 25): 2.520 €
• Deductible VAT (field 44): 304.50 €
• Result to be paid (field 46): 2.215.50 €

This amount must be paid to the AEAT before July 20, 2026. The self-employed individual can domicile the payment until July 15.

Additionally, this self-employed individual is registered in the RETA by real income. If their annual net income forecasts fall within a specific bracket of the 2026 cotization table (published by Social Security), their autonomous contribution 2026 monthly amount will be determined based on that forecast. The coherence between the declaration in the 303 and the income from IRPF is an element that Social Security can cross-check.

If this self-employed individual had recently registered and meets the requirements, they could be eligible for the flat rate of 80 euros for the first 12 months (extendable to 24 months in autonomous communities that apply it), which would reduce their cotization regardless of the result of the model 303.

Common errors when filing the model 303

Knowing the most common errors helps avoid AEAT requests:

• Including invoices without NIF or with incorrect data: the VAT supported is not deductible without a valid complete invoice.
• Not declaring intracommunity operations: if you purchase services from EU providers (e.g., digital advertising platforms), you must apply the reverse charge and reflect it in the corresponding fields.
• Offsetting negative balances without noting them: the previous quarter's offset balance must be transferred to field 67.
• Filing outside the deadline: generates 1 % penalties per full month of delay, up to 15 % after 12 months, according to article 27 of the General Tax Law.
• Not keeping invoices: the AEAT may request documentation during the prescription period (4 years).

Sources and reference legislation

• Law 37/1992, of December 28, on the Value Added Tax (LIVA): regulates the taxable fact, exemptions, deductions, and tax rates. Available in the BOE.
• Law 58/2003, of December 17, General Tax Law: regulates penalties for late filing (article 27).
• AEAT – Electronic Portal: form, instructions, and electronic filing of the model 303. sede.agenciatributaria.gob.es
• Social Security – RETA by real income: cotization tables and contributions for 2026. seg-social.es
• Royal Decree-Law 13/2022: establishes the real income cotization system for self-employed individuals.
• TEAC (Central Economic-Administrative Tribunal): rulings on the deductibility of expenses in economic activities.