June 30, 2026 was the deadline for filing the IRS tax return for 2025 income. If you missed it, you’re not alone — every year, thousands of taxpayers in Portugal file late. The good news is that the system doesn’t close: the Portal das Finanças keeps accepting returns after the deadline. The bad news is that filing late is formally a tax offense and can result in a fine. Here’s how much it costs, why it’s important to act quickly, and how to handle it yourself without an accountant.
Can you still make it?
Strictly speaking, you’ve already missed the window: the official filing period ran from April 1 to June 30, 2026. But you can still — and should still — file. Access to the system isn’t blocked; the Modelo 3 return is submitted through the Portal das Finanças exactly as it would be on time. The only difference is that the filing now counts as "fora do prazo" (out of time), and the tax authority (Autoridade Tributária, AT) is entitled to issue a fine — a coima.
Key point: the sooner you file, the cheaper the delay. The law explicitly rewards voluntarily fixing the situation.
How much is the fine
The base range for a fine for failing to file or filing late is set by Article 116 of the General Regime of Tax Offenses (RGIT): from €150 to €3,750. That sounds alarming, but in practice, for those who correct the situation themselves, the amounts are far more modest.
If you file on your own initiative within 30 days of the deadline — that is, by July 30, 2026 — and before the tax authority sends you a notice, the fine drops to 12.5% of the minimum. That works out to €18.75, but since the law sets a minimum reduced fine of €25, you’ll pay €25. For most people who missed the deadline, that’s the real cost.
If you miss even this "grace" month, the tax authority will send you a notice requiring you to resolve the situation within 30 days. Filing after receiving the notice costs at least €37.50 (12.5% of €300, the minimum for cases of negligence). Fully ignoring the obligation is the most expensive scenario: a fine of €150 to €3,750, plus the tax authority will calculate your tax "officially" (liquidação oficiosa) based on its own estimates and without fully accounting for your deductions — which is almost always worse for you.
Interest is a separate cost. If your return shows tax owed and you don’t pay by the date on the payment notice, daily late interest starts accruing (the 2026 rate is 7.221% annually). If instead you’re due a refund (reembolso), interest isn’t a concern, but the refund itself will arrive later, and the fine may eat into part of it.
What else late filers lose
The fine isn’t the only consequence. Spouses and de facto couples filing after June 30 lose the right to choose joint taxation for that year and must declare income separately — for many families, that’s noticeably more expensive. Also at risk: the permanent exemption from the municipal property tax (IMI), the municipal IRS discount (up to 5% depending on the municipality), and access to government support programs that require a nota de liquidação — such as housing rental subsidies.
There’s also some good news: since 2024, the rules have been relaxed. Late filers no longer lose the right to deductions for expenses confirmed in the e-Fatura system (health, education, housing, general family expenses) — previously this was one of the most painful consequences.
An important detail for those under IRS Automático: if you didn’t confirm or reject your draft return by June 30, the tax authority automatically converted it into a final one. In that case, check it in your account — if everything’s correct, no action is needed; if there are errors, file an amended return.
How to file the return yourself: step by step
The return is filed only online, and it’s realistic to handle it without outside help.
- Log into the Portal das Finanças (portaldasfinancas.gov.pt) using your NIF and password, or via Chave Móvel Digital. If you don’t have a password, you can request one on the portal (it arrives by mail at your registered address).
- Find the IRS section and select "Entregar Declaração" (submit return) for 2025.
- Choose how to fill it out. If a pre-filled return is available to you, most data (salaries, withholdings) is already populated automatically. Otherwise, fill out Modelo 3 manually with the needed schedules: Anexo A — employment income and pensions, Anexo B — self-employed income (regime simplificado), Anexo F — rental income, Anexo J — foreign income, Anexo H — tax benefits and deductions.
- Check the key details: household composition, IBAN for a refund, income and withholding amounts.
- Run the simulation ("Simular") — the portal will show whether you owe more tax or are due a refund, before you submit.
- Submit the return ("Submeter") and be sure to save the filing confirmation (comprovativo).
- Track the status in your account: confirm the return gets the status "Certa" (accepted without discrepancies). If the tax authority finds a divergência, you’ll get a notice asking for clarification.
If the return shows tax owed, pay it per the payment notice as soon as possible — at a Finanças office, via Multibanco, or online banking. If you’re facing financial difficulty, you can request an installment plan: IRS debt can be spread over up to 36 months (minimum payment €25.50 in 2026).
Bottom line
The deadline has passed, but the window for a "cheap" fix stays open until July 30, 2026: file yourself, without waiting for a letter from the tax authority, and you’ll most likely get away with a €25 fine. Every week of delay after that increases both the fine and the risk of further losses.
This material is for informational purposes only and doesn’t replace consultation with a tax professional. Information current as of July 2026.
Sources and useful portals:
Portal das Finanças — filing returns and your personal account
e-Fatura — reviewing and confirming expenses for deductions
Autenticação.gov (Chave Móvel Digital) — login via digital signature
CGD Saldo Positivo — filing IRS late
DECO PROteste — consequences of late filing
Montepio — fines and coima reduction
Idealista — IRS fora de prazo
Doutor Finanças — 2026 IRS calendar
Legal basis: Regime Geral das Infrações Tributárias (Art. 116, 30, 26).
