DT15600 - Double Taxation Relief Manual: Guidance by country: Portugal: Agreements in force

Title: Convention between the government of the United Kingdom of Britain and Northern Ireland and the Portuguese Republic for the elimination of the double taxation with respect to taxes on income and on capital gains and the prevention of tax evasion and avaoidance.

Signed: 15 September 2025

Statutory Instrument number: SI 2025 No. 1300

Entered into force: 29 December 2025

Has effect:

  • In Portugal from 1 January 2026 in respect of all taxes covered
  • In the United Kingdom from 1 January 2026 in respect of taxes withheld as source, 1 April 2026 in respect of corporation tax and 6 April 2026 in respect of income tax and capital gains

The text of the agreement currently in force can be found at the following link:  Portugal: tax treaties - GOV.UK


Title: Convention for the Avoidance of Double Taxation and the Prevention of Fiscal Evasion with Respect to Taxes on Income 

Signed: 27 March 1968

Statutory Instrument number: SI 1969 No. 599

Entered into force: 17 January 1969

Has effect:

  • in Portugal from 1 January 1970
  • in the UK, in respect of income tax and capital gains tax, from 6 April 1970; in respect of corporation tax, from 1 April 1970

 This previous convention applied until the dates from which the above convention took effect.