4 ms·Any card on your account should work, last 4 must match, I have never entered number or scan QRby kay_o 9mo agoAny card on your account should work, last 4 must match, I have never entered number or scan QRarjie 9mo agoOh, then my watch should suffice. Okay, I shall try it next time with a Prime discounted product!kay_o 9mo agoGpay/Apple Pay added card etc will not match hand-entered card on Amazon site's number since last 4 differs IIRCarjie 9mo agoOh thank you for that. That explains it.