What is an Apostille?
An Apostille stamp is a form of authentication added to documents to allow them to be used in member countries of the Hague Convention, and are usually requested by foreign governments to assert that a document is genuine. In the UK this is sometimes known as an FCO Apostille, as the FCO (Foreign & Commonwealth Office) is the governmental body that issues them within the UK.
Once an Apostille stamp is added to a document, it becomes valid for use in any country that is a member of the Hague Convention.