Why did I get the error "57 Terminal is not programmed for this service" when integrating Payflow Pro?

While integrating Payflow Pro, an error message reported a "57 terminal" error.

Your merchant services account doesn't accept the card type your customer selected. For example, you'll get this error if you try to submit an American Express or Discover card while your account isn't enabled to accept those cards.

Contact your merchant services provider to become authorized to accept payments from the card types that produced the error.

In the meantime, to avoid receiving this error, do the following:

  1. Log in to your cart administration page.
  2. Click Cart Settings.
  3. Select Payment/Gateway Settings.
  4. Deselect the box next to the card type that received the error.