If you get that the Cash app won't let me send money without id, then you must read its all terms & conditions which are mentioned below. Actually, the Cash app is a digital payment app, so you must have provided your personal info to verify your identity as well as your account. Along with it, at the time of making any transaction, you are asked to enter the last four digits of SSN. https://www.numbersupportcustomerservice.com/blog/cash-app-wont-let-me-send-money/