All the official documents issued by a UK authority must be legalised to take effect in San Marino.
The documents must have an Apostille stamp, which can be obtained by:
Legalization Office – Foreign, Development and Commonwealth Office
P.O.Box 6255 – Milton Keynes MK10 1XX –
Tel.: 03700 00 22 44
Web address: www.gov.uk/get-document-legalised
After legalising the documents they need to be translated in Italian by a certified translator and notarised.
Citizens need to mail the original documents (after having them legalised & translated in Italian) to the postal address of the Consulate of San Marino in London for further processing:
Consulate of the Republic of San Marino
15-17 Saint Cross Street
EC1N 8UW – United Kingdom