Please check the number you gave us is correct.
If the number is typo free, you may have already linked the given phone number to another account: this means you might have already created a Yoyo account* on which you have verified your phone number. Please try logging in using an alternative email address.
*Note that Yoyo Wallet powers the Caffè Nero app, the Harris + Hoole app, the Coffee#1 app, the PAUL UK App and the Black Sheep Coffee app. The same Yoyo account will be used across all apps with one verified phone number.