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 assistance, please click here to see our contact details. Related articles Livescore Bet Squads Contact us Horse Racing Talk to professionally trained staff Welcome Offer Promotion