Double Taxation Relief Manual: Guidance by country: Spain: Agreement
The comprehensive agreement (SI 1976/1919) has effect
a) In the United Kingdom for
i) Income Tax from 1976-77,
ii) Capital Gains Tax from 1976-77,
iii) Corporation Tax from 1 April 1976.
b) In Spain from 1 January 1976.
An Exchange of Notes concerning the taxation of time share rights (SI 1995/765) has effect from 1 January 1992 see DT17553.
If using the HMRC Intranet, the agreement and exchange of notes can be viewed through the “New treaties/protocols in force” link on the sidebar. On the HMRC web-site, searching for “Treaties in force Spain” will provide a link to the treaty and exchange of notes.
The text of the Tax Treaty can be found via https://www.gov.uk/government/publications/spain-tax-treaties