Advice needed as

Stepfather and Mum will hopefully be collecting their Non Imm (O-A Stepfather) and Non Imm (O Mum) from Uk embassy tommorow fingers crossed, Their UK marriage certificate has been legalised by both the UK FCO and Thai embassy London.        Obviously my mother will only have a 90 day single entry and plans to extend the Visa firstly at 90days then yearly to match my stepfather at a local immigration office. 

    Both parents are UK citizens in their 70s and stepfather meets the financials both by pension and savings.

Question is,

  does the Marriage certificate now need to be translated first & then legalized again by the MFA in Bangkok before applying for my Mum's first extension ??

 

Many Thanks

A translation is not required since the marriage certificate is in English.