Unfortunately, not all US banks support our instant (Manual Now) payments to debit cards, but we’re working hard to get more banks on board.
AMEX cards are not supported on the debit card network. Prepaid debit cards and small banks, like Credit Unions, typically do not work with the instant pay network.
Unfortunately, we are not able to see the exact reason the card is unsupported within the Visa/Mastercard system. You may contact the 1-800 number on the back of the debit card for a further explanation. Alternatively, you can always add another debit card to try an instant payment.