When do I need to file Form 303?

Quarterly: from the 1st to the 20th of April (Q1), July (Q2), October (Q3), and from the 1st to the 30th of January of the following year (Q4). If the deadline falls on a weekend or holiday, it extends to the next business day. There's an option to direct debit the payment, which has a deadline 5 days earlier.

What is output VAT and input VAT?

Output VAT is what you charge your customers (you collect it for the tax authority). Input VAT is what you pay to your suppliers. In Form 303 you declare the difference: if you collected more than you paid, you pay the difference; if you paid more, you offset.

What expenses can I deduct in Form 303?

All expenses linked to your economic activity with an invoice in your name: office rent, utilities, materials, software, phone, accounting, insurance, advertising, business travel. You cannot deduct personal expenses or those without invoices.

What happens if the result is negative?

If your input VAT exceeds output VAT, you have two options: offset that balance in following quarters (box 87 → box 110 of the next quarter) or request a refund in Q4 if you've had accumulated negative balance all year.

Can I request a VAT refund in any quarter?

No. You can only request a refund in the Q4 return (January). In quarters Q1, Q2, and Q3, negative balances can only be offset in subsequent periods. There's an exception: companies registered in REDEME can request monthly refunds.

What's the difference between Form 303 and Form 390?

Form 303 is the quarterly VAT self-assessment. Form 390 is the annual informative summary presenting year totals. It doesn't involve additional payment, only information. Since 2024, many freelancers are exempt from Form 390 if they meet certain requirements.

Form 303 Calculator Quarterly VAT Return

Calculate your quarterly VAT return instantly. Enter your sales and expenses, the calculator tells you how much to pay the tax authorities or offset. Free, no registration required, updated for 2026.

Quarter

Select the quarter you are filing

Output VAT (collected)

VAT you collected from customers on your sales invoices

Sales at 21%

€

Tax base of your invoices with standard VAT

Sales at 10%

€

Tax base of your invoices with reduced VAT

Sales at 4%

€

Tax base of your invoices with super-reduced VAT

Input VAT (paid)

VAT you paid on your deductible expense invoices

Expenses at 21%

€

Tax base of your expenses with standard VAT

Expenses at 10%

€

Tax base of your expenses with reduced VAT

Expenses at 4%

€

Tax base of your expenses with super-reduced VAT

Investment goods

€

Equipment, machinery or other assets (21% VAT)

Compensation from previous periods

Previous period compensation

€

Negative balance from previous quarters to offset

Enter your sales or expenses to calculate Form 303

How to calculate your Form 303

Form 303 is the quarterly VAT self-assessment. Follow these steps to calculate it:

Sum your sales by VAT rate

Group the tax bases of your issued invoices by VAT rate: 21%, 10%, or 4%.

Sum your deductible expenses

Group the bases of your expense invoices. Only include expenses related to your economic activity.

Add investment goods

If you purchased equipment or machinery, add the input VAT as an additional deduction.

Apply previous compensation

If you have negative balances from previous quarters, you can offset them to reduce what you pay.

Key concepts of Form 303

Understanding these concepts is essential for correctly filing your VAT return:

Output VAT

This is the VAT you charge customers on sales invoices. It corresponds to boxes 01-09 of the form.

Deductible Input VAT

This is the VAT you pay on business expenses. It's only deductible if the invoice is in your name and linked to your business.

Settlement Result

Output VAT - Input VAT = Result. If positive, you pay. If negative, you offset or request a refund.

Compensation

If a quarter results in negative, you can carry forward that balance to reduce what you pay in subsequent quarters.

Why use our calculator?

Designed for freelancers who want to file VAT returns without errors or stress.

Form 303 filing without headaches

Precise calculations of output and input VAT. Know exactly how much to pay the tax authorities. No quarterly anxiety, no box errors.

All VAT rates in one place

21%, 10%, 4%, investment goods, and compensation. Everything you need to complete the form — no pocket calculators or complex Excel sheets.

And when you invoice, VAT files itself

This calculator is from Invoo, the software that connects your invoicing with your gestoría. Your Form 303 generates automatically — no copying figures, no paperwork, no emails.

Frequently asked questions about Form 303

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Stop calculating VAT. Start invoicing.

With Invoo, invoice in 30 seconds — your VAT tracks automatically, your gestoría sees Form 303 in real time, and you're Verifactu compliant without thinking. €10.90/month, all included.