guessing they’re using the carrier’s data for verification. name, address, phone number, socials and at least partials of credit cards, bank accounts. whatever relevant that they have.

this is all data the credit bureau has on you already

just a step or two removed from what’s probably their ultimate goal: a unique guid for every device, that you can’t change, can’t remove, can’t decline, and is always with you–including linking multiple devices when you log-in to the same account somewhere across googleland from them.