Hi there, Stacy!
When you make a reservation, either
online or by calling (407) WDW-DINE, you will be asked for a credit card number. This is to guarantee that you will adhere to the cancellation policy of many table service restaurants: a call 24 hours in advance is usually the standard.
You will need to provide the name of each person n your travel party.
For each person in your travel party who does not adhere to the policy, a fee will be assessed on that card (around $10, but this is subject to change without notice).
If, then, your party of 20 becomes a party of 19 at the last minute, the credit card associated with that person's name will be charged the cancellation fee.
Some restaurants - like Cinderella's Royal Table - may have different policies. If you'd like, feel free to send me your specific dining options, and I'll be glad to provide you with the relevant information.
Have a great trip!
See you later, celebrator,
-Deborah B.