How do I sign up to GAMSTOP? How do I sign up to GAMSTOP? To sign up for GAMSTOP, visit https://www.gamstop.co.uk and register your details. You can also call them for free on 0800 138 6518. Lines are open seven days a week from 8am to midnight. If you need additional assistance, please email full details of your query to email@example.com. You can also use our live chat service by clicking here.