Welcome Cassandra! Thanks for visiting us at the Disney Parks Moms Panel.
When making Advance Dining Reservations you will always be required to inform a valid credit card number. Even for those using a Disney Dining Plan, a credit card guarantee will be required when making reservations. You card will only be charged if you don’t show up for your reservation or don’t cancel it accordingly to the restaurant’s cancelation policy.
However, there are a few exceptions. Some dining experiences require guests to pre pay for their meal in advance, when making the reservation. A very popular Character Dining Experience -
Cinderella's Royal Table - is an example of this situation. During reservation process, the system will inform you if the restaurant chosen requires pre-payment before you finish your reservation.
Hope this helps. Please, let us know if you have further questions.
Have fantastic day!
Gina V.