IRS is Portugal’s personal income tax — Imposto sobre o Rendimento das Pessoas Singulares — and if you’re a tax resident here, filing an annual return is not optional. The good news is that for most people the process is done entirely online, a lot of it is pre-filled, and the deadlines are fixed and generous. The bad news is that foreign income, first-year residency and double-taxation rules trip up newcomers every single spring. Here’s how the whole thing actually works.
Do you even have to file?
You are generally required to file an IRS return if you are tax resident in Portugal — that means you spent 183 or more days here in the calendar year, or you keep a home in Portugal that you treat as your habitual residence. Residency is decided per calendar year, so the year you arrive can be split or partial depending on your circumstances.
If you’re resident, you declare your worldwide income — salary, self-employment, pensions, rental income, dividends, capital gains, the lot — regardless of where it was earned or paid. Non-residents only declare Portuguese-source income, and often through a simpler process. Being taxed abroad on some of that income does not remove the Portuguese filing obligation; it’s handled through double-taxation relief, which we’ll get to.
A few people are exempt from filing (for example, those whose only income is a small amount of already-taxed Portuguese employment or pension income below the legal thresholds), but if you have any foreign income at all, assume you must file.
The window: 1 April to 30 June
This is the single date range to memorise. The IRS filing season for the previous year’s income runs from 1 April to 30 June, every year, with no distinction between employment and self-employment income anymore. So the return covering your 2025 income is filed between 1 April and 30 June 2026.
Miss it and you’re into late-filing territory: penalties start at a fixed minimum and climb, and you lose the right to certain deductions and to a smooth automatic assessment. File on time even if you can’t pay immediately — the penalties for late filing and late payment are separate problems.
If a refund is due, it typically lands over the summer, often within a few weeks to a couple of months of submitting, sometimes faster for straightforward automatic returns. If you owe, the assessment (nota de liquidação) tells you how much and by when — usually by 31 August.
Here is the whole thing at a glance — the dates, who files, and the annexes you’re likely to touch:
| Item | Detail |
|---|---|
| Who must file | Tax residents (183+ days in the year, or a habitual home here) — on worldwide income |
| Non-residents | Portuguese-source income only, often via a simpler process |
| Filing window | 1 April – 30 June (for the previous calendar year’s income) |
| Where | Portal das Finanças — needs your NIF and portal password |
| Payment deadline (if you owe) | Usually by 31 August |
| Main annexes | A (employment/pensions), B (self-employment, simplified), C (organised accounting), E (investment income), G (capital gains), H (deductions/benefits), J (foreign income) |
Step by step on Portal das Finanças
Everything happens on the Portal das Finanças, the tax authority’s online portal. You’ll need your NIF and your access password — if you don’t have a portal password yet, request one early, because it’s posted to your registered address and takes days to arrive. Get your NIF sorted first if you haven’t.
- Log in and go to IRS → Entregar Declaração (submit return).
- Check your household and personal details — marital status, dependents, whether you’re filing jointly or separately. Couples can choose either; run both to see which is cheaper.
- Review the pre-filled data. Finanças pre-populates Portuguese salaries, pensions, withholdings and many deductions from the e-fatura system. Do not blindly trust it — verify every figure against your own records.
- Add the annexes you need. Anexo A (employment/pensions), Anexo B (self-employment under the simplified regime), Anexo C (organised accounting), Anexo E (investment income), Anexo G (capital gains), Anexo H (deductions/benefits) and crucially Anexo J for foreign income.
- Enter foreign income on Anexo J — every foreign salary, pension, dividend, interest payment, rental and gain, plus the foreign tax you already paid.
- Validate. The portal runs error checks; fix any red flags before submitting.
- Submit and save the receipt (comprovativo). Keep it. Keep everything for at least four years — Finanças can review going back.
For simple cases, Finanças may offer an IRS Automático — a fully pre-filled return you just confirm. It’s only available to specific profiles (typically employment/pension income, no foreign income, standard deductions). If you have foreign income, you will not qualify and must file manually.
Foreign income and double-taxation relief
This is where expats get anxious, usually unnecessarily. Portugal has double-taxation agreements with most countries, including the UK, the US, and across the EU. The mechanism is simple in principle: you declare the foreign income on Anexo J, declare the foreign tax paid, and Portugal grants a credit for that foreign tax (or exempts the income) so you’re not taxed twice on the same euro.
What actually matters in practice:
- Which country has taxing rights depends on the type of income and the specific treaty. Employment income is usually taxed where the work is performed; pensions and dividends have their own rules.
- US citizens file in both countries regardless — the US taxes on citizenship. The treaty and foreign tax credits stop true double taxation, but you keep two filing obligations.
- The credit is limited to the Portuguese tax that would have been due on that income; you don’t get a refund of excess foreign tax from Portugal.
If your income is genuinely international, this is the part to get professional help with. A wrong entry on Anexo J is the most common expensive mistake we see.
Deductions worth claiming
Portuguese IRS lets you deduct a range of household expenses, mostly captured automatically through e-fatura when you give your NIF at the till. Health, education, general family expenses, property (rent or mortgage interest within limits), and some VAT on invoices from sectors like restaurants and car repairs all count. Log into e-fatura through the year and classify your invoices — unclassified ones may not count. It’s tedious but it’s real money back.
If you moved here under IFICI (the successor to NHR) or have other special regimes, those interact with your return too — see our tax and NIF pillar for the residency picture, and get advice on how the regime flows into your annexes.
Common mistakes
- Assuming foreign tax means no Portuguese filing. You still declare it on Anexo J.
- Trusting the pre-filled figures blindly. Verify against payslips and statements.
- Forgetting Anexo J entirely — the most frequent omission for newcomers.
- Not classifying e-fatura invoices, then wondering why deductions are lower than expected.
- Filing separately when jointly is cheaper (or vice versa) — model both.
- Leaving it to 29 June. The portal slows to a crawl at the deadline; file in April or May.
Short FAQ
When exactly do I file? Between 1 April and 30 June for the previous calendar year’s income.
Where? Online at Portal das Finanças. You need a NIF and portal password.
Do I declare income earned abroad? Yes, if you’re tax resident — worldwide income goes on the return, with foreign income on Anexo J and relief for foreign tax paid.
What if I owe tax? The assessment sets the amount and deadline, usually payable by 31 August.
I’m self-employed — is it different? Yes; you’ll use Anexo B and there are extra steps. See our freelancer tax guide and social security guide.
Tax outcomes depend on your specific facts and the treaties involved, and the rules change, so treat this as a map rather than personalised advice. When foreign income or special regimes are in play, get it checked.
Nervous about your first Portuguese IRS return, or juggling income from more than one country? GrowIN Portugal’s advisors file it correctly and claim what you’re owed. Explore our services to get started.