Apple Pay would let any app do this. The merchant could send a push notification to their own app on your phone, which would get the transaction details and re

Apple Pay would let any app do this. The merchant could send a push notification to their own app on your phone, which would get the transaction details and request payment via Apple Pay, which would have already been set up on your phone. The reason this doesn't exist now is because of the way banks and credit cards work. They're issuer-centric, not user-centric. Your credit card isn't yours. It's your bank's, and it's issued in partnership with the credit card network provider, MasterCard or Visa. The credit card network provider has the relationship with the merchant, which is why some merchants don't take Discover or American Express. Both the bank and the credit card network make money off of fees from the merchant. Yes, it's you who has to spend the money, but you're not the customer of the two people with the power (the bank and the credit card network): you're ancillary in their equations. You're only valuable to the merchant, and the merchant would prefer you to pay in cash. Apple Pay is the first to do this for the exact reasons they stated at the launch: they're not trying to make money off the transaction. They're making money off of you, the user, by selling you hardware. So it's in their best interest to give you this great feature, which is user-centric payment, abstracting away the merchant and the bank and the credit card network, because it sells you hardware. Cell phone networks have the same problem; your SIM card isn't yours, it's your network provider's, despite being your electronic ID to them. There's no way for you to consolidate or control all these pieces of your digital ID, and there's no incentive with the way the industries are set up to allow you to.