The legalisation convention is the convention abolishing the requirement of legalisation for foreign public documents, also known as the Apostille Convention (5 October 1961). This convention does not completely abolish legalisation but shortens the chain so that only a single action is required, the addition of an apostille. A document bearing an apostille does not require any further legalisation by the embassy or consulate of the country in which it is to be used.
Apostille for Mongolia -
If your document originates from Mongolia then it should be legalised by the correct authority where the document was created or issued. For any document issued in Barbados we suggest you try to contact the following apostille authority:
Address the Ministry of Foreign Affairs and Trade of Mongolia