Good question!
"this gift card can only be used in full or part payment of tickets to participating events and other qualifying items throughTicketmaster by phone, ticketmaster.co.uk and at participating ticket centre outlets and venue box offices. Not accepted for non UK events"
It expires 12 months after purchase though Im not sure when that was, my hubby bought them off someone he works with but we dont need them anymore, cant get a babysitter for what we wanted to go to x