# Autoridade Tributária e Aduaneira (Portuguese Tax Authority)

> Portugal's tax authority. Accepts up to €0.40/km tax-free for own-vehicle business mileage reimbursement.

**URL:** https://quilometragem.com/glossary/autoridade-tributaria

**Summary:** Accepts up to €0.40/km tax-free for own-vehicle business mileage reimbursement.

- The Portuguese AT administers income tax (IRS), corporate tax (IRC), VAT and customs.
- For own-vehicle business mileage, the tax-free reimbursement cap is €0.40/km, unchanged into 2025 and 2026.
- Anything above is subject to IRS and Social Security contributions.
- Required documentation: itinerary slip (boletim de itinerário) with date, origin, destination, purpose, plate and kilometres, retained for 10 years.

The Portuguese AT administers income tax (IRS), corporate tax (IRC), VAT and customs. For own-vehicle business mileage, the tax-free reimbursement cap is €0.40/km, unchanged into 2025 and 2026. Anything above is subject to IRS and Social Security contributions. Required documentation: itinerary slip (boletim de itinerário) with date, origin, destination, purpose, plate and kilometres, retained for 10 years.