If you've ever Googled "how to fill in Modelo 303," you've probably found yourself drowning in articles that explain all 100+ boxes of the form. Here's the good news: if you're a regular autónomo (you provide services, invoice mainly in Spain, and occasionally bill a client abroad), you only need to fill in about 10-15 boxes.
This guide is for you if:
You're an autónomo or small company (SL) in Spain, you're registered in Régimen General for VAT purposes, and you file your Modelo 303 quarterly. Most freelancers and service providers fall into this category.
This guide is NOT for you if:
You're in Régimen Simplificado (módulos). Typically bars, taxis, and certain small retail businesses. You're required to file monthly because your turnover exceeds €6 million. You only do activities exempt from VAT.
Not sure which regime you're in? If you provide professional services and didn't specifically choose módulos when registering as autónomo, you're in Régimen General.
For information about filing deadlines and frequently asked questions, check out our article on Modelo 303 deadlines and FAQs.
How to access Modelo 303
Go to the AEAT electronic office. You'll need to identify yourself using a digital certificate, electronic DNI (DNIe), or Cl@ve PIN.
Initial screen: identification data
When you first access the form, you'll see a popup asking for basic information. Ejercicio is the year you're filing for, such as 2025, Periodo is the quarter: 1T, 2T, 3T, or 4T, NIF is your tax ID number (DNI/NIE) and apellidos y nombre is your full name.
If you use invoicing software like Facturaz, you can generate a pre-filled Modelo 303 file and import it directly using the "Importar" button. This saves tons of time and you'll only need to review the data before submitting.
The toolbar
Once inside, you'll see a toolbar that stays visible on every page. Apartados lets you jump to specific sections. Vista previa shows a preview of your declaration. Validar checks for errors (always use this before submitting). The navigation arrows move you between the 5 pages. Seleccionar Ingreso/Devolución is the final submission button.
Page 1: identification
This page looks intimidating with all its options, but for a standard autónomo, almost everything stays blank or set to "NO."
- Tributa exclusivamente en régimen general should be YES. This is standard for service providers.
- Exonerado del modelo 390 might be YES if you only do urban rentals or are in the SII system.
Everything else you can ignore: Registro de devolución mensual is for large companies. Régimen simplificado is for bars, taxis, and módulos businesses. Criterio de Caja only applies if you specifically opted in. Prorrata especial is only for mixed exempt/taxable activities. SII is mandatory only for turnover above €6M. And
Concurso de acreedores is for bankruptcy and hopefully not applicable to you.
Page 2: the heart of Modelo 303
This is where the actual calculation happens. It has three sections: VAT charged, VAT deductible, and the result.
IVA Devengado: the VAT you charged
This section captures the VAT from all invoices you issued during the quarter.
- Casillas 07, 08, 09 are for the 21% rate—the most common. Your standard service invoices go here. Box 07 is the tax base, and box 09 is the VAT amount.
- Casillas 04, 05, 06 are for the 10% reduced rate, used for hospitality, transport, and similar services.
- Casillas 01, 02, 03 are for the 4% super-reduced rate, which applies to things like bread and books. This is rare for service providers.
- Casillas 10 and 11 are for intra-EU purchases. This is important: if you buy services from EU companies like hosting, software, or advertising, they don't charge you VAT. But you must declare the amount here and then deduct it below. The net effect is zero, but it's mandatory.
Many people get caught out by casillas 10 and 11. If you use services from companies like AWS, Google Ads, Mailchimp, or Stripe, you need to self-assess the VAT here even though they didn't charge you.
You can ignore the recargo de equivalencia section because that's for retail shops, not services. Modificación bases y cuotas in boxes 14-15 is only for correcting previous quarters. Other inversión sujeto pasivo in boxes 12-13 covers very specific construction and gold-related cases.
IVA Deducible: the VAT you can deduct
Here's where you recover the VAT you paid on business expenses.
- Casillas 28 and 29 are for current expenses—the VAT on day-to-day costs like office supplies, software, professional services, phone, and internet. Box 28 is the base amount, and box 29 is the deductible VAT.
- Casillas 30 and 31 are for investment goods—major purchases over €3,005.06 with a useful life of more than one year, such as computers, office furniture, or professional vehicles.
- Casillas 36 and 37 are for intra-EU purchase deductions. If you declared intra-EU purchases above in boxes 10-11, you deduct the same VAT here. The net effect is zero.
Remember that you can only deduct VAT on expenses related to your professional activity. A dinner with friends doesn't count, but a business lunch with a client does—at 50% if there's no overnight stay.
You can ignore imports in boxes 32-35 unless you import goods from outside the EU. A.G.P. compensations in box 42 are for farmers and ranchers. Investment goods regularization in box 43 only applies in Q4 if your prorrata percentage changed.
Result section
Casilla 46 equals box 27 (total VAT charged) minus box 45 (total VAT deductible).
A positive result means you owe money to Hacienda. A negative result means Hacienda owes you, though this is usually compensated in future quarters rather than refunded immediately.
Page 3: régimen simplificado
Skip this page entirely. It's exclusively for autónomos in the módulos system—certain bars, taxis, and small shops with estimated taxation. If you're a service professional on régimen general, there's nothing for you here.
Page 4: additional information
This page is informational only. The amounts here don't affect your VAT calculation, but Hacienda wants to know the volume of certain operations.
- Casilla 59 is for intra-EU services—services you provided to EU businesses, invoiced without VAT to clients with a valid VAT number. Enter the total tax base here.
- Casilla 60 is for exports—services or products sold outside the EU to countries like the USA, UK, or Latin America. These are also without VAT.
- Casilla 120 is for other non-subject operations—services not subject to Spanish VAT due to localization rules.
Even though you didn't charge VAT on these operations, you must declare them here. It's just information, but omitting them can trigger inquiries from Hacienda.
You can ignore inversión sujeto pasivo in box 122, which covers specific cases within Spain. OSS/Ventanilla única in boxes 123-124 only applies if you sell to EU end consumers. Criterio de caja in boxes 62, 63, 74, and 75 only matters if you opted into that regime.
Page 5: final result
This is the home stretch where your final amount is calculated.
- Casilla 64 shows the sum of results, pulling from box 46 on page 2.
- Casilla 65 is the percentage for State Administration—always 100% unless you're in Basque Country or Navarra.
- Casilla 66 shows what's attributable to the State, which is the same as box 64 for most people.
- Casilla 110 shows amounts to compensate from previous periods. If previous quarters had negative results that you left "to compensate," that balance appears here.
- Casilla 78 shows how much of that balance you're applying this quarter.
- Casilla 87 shows what remains pending for future quarters.
- Casilla 71 is the final result—the magic number. Positive means you pay, negative means you can compensate or request a refund.
You can ignore import VAT from Customs in box 77 unless you're an importer. Foral annual regularization in box 68 only applies to Basque Country and Navarra. The rectificativa boxes 70, 108, 109, and 111 are only for correcting previous declarations.
Sin actividad: no activity
If you didn't issue any invoices and had no deductible expenses during the quarter, simply check the "Sin actividad" box. You're still required to file, but the form will be essentially empty.
Rectificativa section
This is only used if you need to correct a previously submitted declaration. For normal quarterly filing, ignore it completely.
How to submit
Start by clicking "Validar" in the toolbar and fix any errors that appear. Then use "Vista previa" to review that everything looks correct. Click "Seleccionar Ingreso/Devolución" to proceed to submission.
If box 71 is positive, select "Ingreso" and enter your bank account for direct debit. If box 71 is negative, select "A compensar" to use the credit in future quarters, or "Solicitar devolución" to request a refund though most autónomos can only request refunds in Q4. If box 71 is zero, simply submit.
If you're not using direct debit, you'll need to obtain an NRC (Número de Referencia Completo) before submitting. The NRC is a 22-character code that serves as proof of payment. You can generate it directly from the form by clicking "Realizar pago (obtener NRC)", which connects you to the payment gateway. Once you have the NRC, enter it in the "Número de Referencia NRC" field and click "Firmar y Enviar".
Alternative payment methods: You can also pay by bank transfer from a non-collaborating bank by selecting "Reconocimiento de deuda y pago por transferencia" from the dropdown. For individuals and entities without legal personality filing quarterly, there's a new option: "Documento para ingresar en Banco/Caja". This submits your declaration electronically but generates a payment document you can take to a bank branch to pay in person.
After successful submission, you'll see "Su presentación ha sido realizada con éxito" and receive a PDF containing your submission details (entry number, Secure Verification Code, receipt number, date and time) plus a complete copy of your declaration. Save this PDF, it's your proof of compliance.
If you can't pay immediately, you can request a payment plan (aplazamiento) or offset against other tax credits (compensación) by clicking "Tramitar deuda" on the confirmation page.
Practical example
María is a freelance designer. In Q1 2025, she issued three invoices to Spanish clients totaling €5,000 plus €1,050 VAT. She also invoiced a German company €2,000 without VAT as an intra-EU service, and a US company €1,500 without VAT as an export.
Her deductible expenses included €100 for hosting from an Irish company with no VAT charged, €50 plus €10.50 VAT for Adobe software from a Spanish company, and €100 plus €21 VAT for office supplies.
- On page 2 for IVA Devengado, she enters 5,000 in box 07 and 1,050 in box 09 for her national sales at 21%. She enters 100 in box 10 and 21 in box 11 for the self-assessed Irish hosting. Her total in box 27 is €1,071.
- For IVA Deducible, she enters 150 in box 28 and 31.50 in box 29 for Adobe and office supplies. She enters 100 in box 36 and 21 in box 37 for the intra-EU hosting deduction. Her total in box 45 is €52.50.
- The result in box 46 is €1,018.50—the amount she needs to pay.
- On page 4, she enters 2,000 in box 59 for her invoice to Germany and 1,500 in box 60 for her invoice to the USA.
- On page 5, her final result in box 71 is €1,018.50. María must pay this amount to Hacienda.
Final tips for filing Modelo 303
- Use invoicing software. Tools like Facturaz calculate everything automatically and generate a file you can import directly.
- Keep your books up to date. It's much easier to file the 303 if you record invoices and expenses as they happen, not on the last day of the deadline.
- Save all invoices. Keep both the ones you issue and the ones you receive. Hacienda can request them up to 4 years later.
- Don't wait until the last day. The AEAT website tends to crash on deadline days.
- When in doubt, ask. AEAT has an information line at 901 33 55 33, and you can also book in-person appointments for complex questions.
Quick reference: the boxes most freelancers need
- On page 1, most boxes stay blank. Just confirm you're on régimen general.
- On page 2, the key boxes are 07-09 for your sales, 10-11 for intra-EU purchases you need to self-assess, 28-29 for your deductible expenses, 36-37 for intra-EU deductions, and 46 for the result.
- Page 3 can be skipped entirely since régimen simplificado doesn't apply to service providers.
- On page 4, use boxes 59, 60, and 120 to report any international invoices. This is informational only.
- On page 5, the important boxes are 64 for the sum, 71 for your final result, and 110 and 78 if you're compensating from previous quarters.
What changes in 2026
The 2026 version of Modelo 303 has very few changes compared to 2025, and none of them affect how a typical autónomo fills in the form.
- eIDAS authentication has been added as an identification option. You can now access the AEAT platform using the European electronic identification system (eIDAS) in addition to the existing options of digital certificate, DNIe, and Cl@ve PIN.
- CNAE codes updated to reflect the CNAE-2025 classification approved by Real Decreto 10/2025. This only matters if you need to fill in the prorrata section on page 5, which most autónomos don't.
All casillas, calculations, deadlines, and procedures remain exactly the same. If you filed Modelo 303 in 2025, you'll find no surprises in 2026.
