An Apostille stamp or an Apostille Certificate is an official certificate issued to documents so that they can be recognised and used in member states and countries.  The Apostille Certificate confirms that the document is genuine so that it can be accepted when used in another country.

United Kingdom joined the Hague Apostille Convention on January 24, 1965. (Convention of 5 October 1961 Abolishing the Requirement of Legalization for Foreign Public Documents).

In the UK, the designated Competent Authority to issue an apostille is The Foreign and Commonwealth Office

 UK OVERSEAS TERRITORIES CONTACT DETAILS HERE