Portugal's 2026 tax season opens with digital-only filings by June 30

The 2026 tax season in Portugal has begun, with all taxpayers required to file their income tax returns between April 1 and June 30. This year's declarations will cover earnings from January 1 to December 31, 2025, with the process now fully digital through the Tax Portal. Taxpayers must submit their returns exclusively via the Tax Portal, where the Tax and Customs Authority (AT) provides a pre-filled declaration. The system calculates income tax (IRS) based on total earnings, including salaries, pensions, rental income, and other sources.

Some eligible taxpayers can use the Automatic IRS feature, which speeds up filing for simpler tax situations. If these taxpayers do not confirm the provisional return by June 30, the AT's proposed declaration becomes their final submission. The payment deadline for those filing by June 30 is August 31. After processing, taxpayers will either receive a refund, owe additional tax, or have no balance due. Those with assets in low- or zero-tax jurisdictions must also disclose this information in their return. No official figures exist yet on how many taxpayers qualify for Automatic IRS in 2025, as 2026 data remains incomplete.

The filing window closes on June 30, with payments due by August 31 for those who meet the regular deadline. Taxpayers must ensure all 2025 earnings are accurately reported, as the AT's system will finalise returns automatically for those using the simplified process.