Apple Pay suddenly asking for a lot of personal data from me before I can accept a payment

I've been using Apple Pay for over a year. Today it is subjecting me to a questionnaire, asking for personal data, before I can accept a $45 payment from my son, who's reimbursing me for something. The questionnaire wants my full name, street address and zipcode, last 4 digits of my SSN, and my date of birth, and possibly some other things. I stopped at that point. Is this LEGIT and from Apple, or is it possible my son's phone has been hacked and this is a third-party app collecting info?