In short: In Portugal, the IRS return is filed once a year, online only through the Portal das Finanças, between 1 April and 30 June (in 2026, for income earned in 2025). You can confirm IRS Automático where it is available, or fill in the Modelo 3 form. This text is for information only and is not tax advice; if in doubt, check with the Autoridade Tributária or a certified accountant.
In Portugal, personal income tax is called IRS. Once a year you report the previous year’s income to the tax authority (Autoridade Tributária), which then works out whether you owe tax or are due a refund. In 2026 you declare income earned in 2025. For most employees and pensioners the process is now quite simple thanks to IRS Automático, but it still pays to understand the basics so you do not miss deadlines or deductions.
Gather last year’s records: payslips or pension statements, proof of any other income, and an idea of the invoices already validated in e-Fatura.
Log in to the Portal das Finanças with your NIF and password (or Chave Móvel Digital) and open the IRS section, between 1 April and 30 June.
Check whether IRS Automático is available: if it is, review the pre-filled return; if not, complete the Modelo 3 form with the right annexes.
Submit the return, save the confirmation, and follow up on the assessment note and any refund in the months that follow.
What matters
IRS (Imposto sobre o Rendimento das Pessoas Singulares) is the tax on the income of people who live in or earn income in Portugal. It works through progressive brackets: the higher your taxable income, the higher the rate applied to the upper portion. During the year, employees and pensioners already have tax withheld at source; the annual return is there to settle up and apply the deductions you are entitled to, which can lead to a refund or to extra tax to pay.
The core document is the Modelo 3 return, submitted on the Portal das Finanças. Many taxpayers can use IRS Automático: the tax authority prepares a return pre-filled with the data it already holds (salaries, pensions, invoices validated in e-Fatura) and you simply confirm it. IRS Automático is aimed mainly at people who had only employment income (category A) and/or pensions (category H) and were resident all year; those with self-employment income, rents, capital income or capital gains usually complete the Modelo 3 manually.
The 2026 calendar (for 2025 income) has key dates: filing runs from 1 April to 30 June; invoice validation in e-Fatura happens earlier, in early March; the tax authority issues the assessment note (nota de liquidação) by 31 July; and tax payment or refund is referenced to 31 August, when the return is filed on time. These dates and the amounts involved can vary year to year — always confirm with the official source if in doubt. This content is educational and does not replace personalised tax advice.
ExampleA simple, rounded example (as of 2026, illustrative figures): a single employee earned about 20,000 € in 2025. The standard employment deduction of about €4,462 applies, leaving taxable income near 15,500 €. The progressive IRS bracket table is applied to this amount, and deductions to the tax due (health, education, general expenses, etc.) are then subtracted. If the tax withheld during the year exceeds the final tax, the difference comes back as a refund; if it was lower, there is tax to pay. The exact amounts depend on the tables and limits in force — when in doubt, confirm with the official source.
Do the maths calmly first. In Kontoo you can organise the year’s income and expenses so you reach your return with everything to hand; then submit on the Portal das Finanças.
In depth
Income categories
IRS organises income into categories (A employment, B self-employment, E capital, F property, G capital gains, H pensions). The category determines the Modelo 3 annexes and affects who can use IRS Automático. Knowing your category helps you understand what you must report.
Deductions to the tax due
Health, education, housing, care-home and other expenses can reduce your tax, within limits. Many depend on invoices issued with your NIF and validated in e-Fatura. So validating invoices on time, in March, is a step that can be worth real money.
Note: this is not advice
This chapter explains how IRS works in general, for educational purposes. It is not tax, legal or financial advice. Particular situations — the self-employed, rental income, inheritances, part-year residence, special regimes — call for confirmation with the Autoridade Tributária or a certified accountant.
Checklist
I know filing runs from 1 April to 30 June 2026 (for 2025 income).
I have access to the Portal das Finanças (NIF and password or Chave Móvel Digital).
I validated the relevant invoices in e-Fatura within the March deadline.
I know whether I can use IRS Automático or need to fill in the Modelo 3 manually.
Common myths
Myth: IRS Automático handles everything, I never need to check anything.
Reality: Even when the return is pre-filled, it is worth reviewing your household, income and deductions. A missing item can mean a smaller refund or too much tax.
Myth: If I do not file, nothing happens.
Reality: People outside IRS Automático who do not file can face a fine, interest and a delayed refund. The obligation is only met with a return filed or automatically converted into the final one.
Frequently asked questions
Do I really have to file if I earn very little?
There are cases where low earners are exempt from filing, but the rules have conditions and exceptions. If in doubt, it is always worth checking your own situation on the Portal das Finanças or with a professional, so you do not miss a possible refund.
What happens if I do not confirm IRS Automático?
If you qualify for IRS Automático and do nothing within the deadline, the provisional return is automatically converted into the final one when the period ends. There is no fine for this, but you lose the chance to correct data or add deductions.
What if I file late?
Filing after 30 June is possible, but it can trigger a fine and delay any refund. Those who owe tax may also face interest. It is best to submit within the deadline, even if only to confirm the automatic return.
