UK Landlord Forum / Life

Hi.
Im about to take section 8 action but have realised that when the original AST was set up only one of the tenants signed the AST, this was as the other tenant was not there at the time.The tenants are a married couple.
Is this going to be an issue with the section 8 notice, and can I only send the notice to the tenant who signed the AST.Both names are recorded on the AST though.
Appreciate any advice.