12-digit number on back of oyster card Home › Forums › Using Oyster › 12-digit number on back of oyster card This topic has 2 replies, 2 voices, and was last updated 1 year, 8 months ago by Mike (admin). Viewing 3 posts - 1 through 3 (of 3 total) Author Posts 27/04/2023 at 22:39 #4879 DuncanParticipant Hi there, are the 12-digit number at the back of Oyster cards meant to be kept confidential/private just to confirm? 27/04/2023 at 22:53 #4880 DuncanParticipant And btw, just to add on, I had also topped up once and got a receipt but then lost it, it might’ve also had my card number! 28/04/2023 at 00:19 #4883 Mike (admin)Keymaster Yes, you should keep the Oyster card number to yourself. It won’t be printed on receipts as far as I know, and certainly not in full. Author Posts Viewing 3 posts - 1 through 3 (of 3 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In