under Maintenance/Payments/Tenders, pull up the credit card in question and go to the identification tab.. Verify that you have the flag "Require Identification" flagged. If this is not flagged, then there will not be a card number field. For the prompt box, I use Card # but this is a free text field so you could put what you wanted. Next make sure you have numbers in the minimum and maximum digits fields and that both are not set to 0, if they are then you cannot enter the card number manually. You should not even be able to enter the expiration date either since moving from the card field to the expiration date field will yield "Invalid prefix" error. Try that out and see if this is your issue.