Chaim Gartenberg, writing for the Verge;
Apple was forced to release iOS 11.2 on Saturday, which was a little earlier than planned, due to a software bug. Now, Apple Pay Cash — one of the marquee features of the update — is being activated for users.
Apple Pay Cash lets users send and receive money directly though iMessages, similar to Venmo or Square Cash. Money that people send you will live on a digital Apple Pay Cash card in the Wallet app, which users can spend anywhere that Apple Pay is accepted, or send to other people. (The new feature is only available in the US for now, though.)
If you updated to iOS 11.2, that means Apple Pay Cash is already on your phone it’s just disabled.