See the following Apple Support article for information on Apple Cash identity verification, including but not limited to the following from that support article. Identity verification for Apple Card or Apple Cash - Apple Support
When you'll be asked to verify your identity
You'll be asked to verify your identity based on how much you use Apple Cash. You may not add or receive $500 or more in total without verifying your identity. You might also be asked to verify your identity prior to this limit.
To protect your account and the security of your money, you might be asked to verify your identity when using Apple Cash, even if you have previously done so.
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Why you'll be asked for your personal data
Apple Cash services are provided by Green Dot Bank, Member FDIC, a regulated financial institution. Green Dot Bank is required by federal law to verify the identity of its customers.
To verify your identity, Green Dot Bank will request Social Security numbers and other personal information to ensure that customers are eligible to use the service.