Unfortunately, not all US banks support our instant (Now) payments to debit cards, but we’re working hard to get more banks on board.
AMEX and Discover cards are not supported our the debit card network. Prepaid debit cards and small banks, like Credit Unions, occasionally do not work with our instant pay network as well.
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 or to have third party transfers enabled for your card. Alternatively, you can always add another debit card to try an instant payment.