The main agreement (SR and O 1947/66) has effect
(a) In the United Kingdom for
(i) Income Tax from 1947-48,
(ii) Corporation Tax from 1 April 1964.
(b) In Belize (formerly British Honduras) for the year of assessment beginning 1 January 1947.
Further agreements (SI1968/573 and SI1973/2097) amending certain provisions of the main agreement entered into force on 8 March 1969 and 12 December 1973 respectively.
The text of the Tax Treaty can be found via https://www.gov.uk/government/publications/belize-tax-treaties