How to file IRS in Portugal in 2026: 9 steps for your tax return

Filing your IRS tax return in Portugal is rarely anyone’s favourite task, but the system is more straightforward than it first appears. If you’re a tax resident declaring income earned in 2025, the submission window runs until 30th June 2026.

How to file your income tax return in Portugal

Step 1: Check your login details early

Before doing anything else, make sure you can log in to the Portal das Finanças using your NIF (tax number) and password. If you’ve forgotten your password, request a new one as soon as possible, as it can take a few days to arrive.

If you have two‑factor authentication activated, keep your phone nearby.

Step 2: Gather the documents you may need

Even though much of the return is pre‑filled by the Autoridade Tributária e Aduaneira (AT), it helps to have key documents to hand, especially if you:

• Sold property, shares or crypto assets
• Received rental income
• Earned income abroad
• Paid or received alimony
• Want to double‑check deductible expenses

Step 3: Log in and see if you qualify for Automatic IRS

Once inside your personal area, the system will indicate whether you’re eligible for Automatic IRS. If you are, you’ll see a pre‑completed declaration with a provisional tax calculation. If not, you’ll need to proceed with Modelo 3.

Step 4: Review all pre‑filled information carefully

This is the part where attention really matters. Check:

• Personal details and tax residency status
• Marital status and household members
• Income amounts
• Deductions for health, education and housing

If you are a foreign resident with income abroad, make sure everything that should be declared is included. Foreign income usually needs to be reported in Annex J of Modelo 3.

Step 5: Add any missing income or deductions

If you notice that something is missing, this is the stage to correct it. Once you begin adding or changing information, you move out of the Automatic IRS system and into the standard filing process using Modelo 3.

• For example, income such as rental income (Annex F) or capital gains (Annex G) must be declared manually in the relevant annexes.
• If you are a foreign resident with income earned abroad, take extra care to ensure everything is properly included. Foreign income generally needs to be declared in Annex J of Modelo 3.

Step 6: Decide on aggregation if relevant

Some income, such as rental income or certain capital income, may be taxed separately at flat rates or included (aggregated) with your other income.

The portal allows you to simulate both scenarios. Many residents run the simulation before submitting to see which option results in a lower overall tax bill.

Step 7: Validate and simulate

Before submitting, click the validation option to check for errors. The system will flag missing fields or inconsistencies.

Then run the simulation to see the estimated result:

• Refund due
• Additional tax to pay
• Or a neutral outcome

Step 8: Submit the declaration

Once everything looks correct, submit the return. After submission, you will receive confirmation in your personal area.

If you later realise you made a mistake, you can submit a replacement declaration within the legal time limits.

Step 9: Monitor the settlement and refund or payment

After submission, the Tax Authority processes the return and issues the final assessment.

• If you are due a refund, payment is usually made by bank transfer to the IBAN registered in your profile.
• If you need to pay additional tax, the payment deadline is 31 August 2026.

A practical example: how IRS is calculated in Portugal

Freepik

You earned €25,000 in 2025. 

1. In Portugal, income tax is not applied to your full gross salary.
   1. Employees benefit from a standard specific deduction (dedução específica) for Category A income. 
   2. For 2025 income, this fixed amount is €4,587.09.
   3. Subtracting this deduction gives your taxable income:
      €25,000 − €4,587.09 = €20,413 (rounded).
2. Under the 2026 IRS brackets, €20,413 falls into the 4th bracket (€17,504 to €22,220), with a marginal rate of 25.50%.
   1. Portugal applies progressive taxation. This means each slice of income is taxed at its corresponding rate:
      1. The first €8,342 at 12.50%
      2. The portion up to €12,600 at 15.70%
      3. The portion up to €17,504 at 21.20%
      4. The remaining amount up to €20,413 at 25.50%
3. Adding these amounts together results in a total IRS due of approximately €3,493.
   1. IRS is withheld from your salary throughout the year.
      1. If more than €3,493 was withheld, you receive a refund.
      2. If less was withheld, you pay the difference, typically by 31st August.

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