Hi Dianna!
Welcome back to the Disney Parks Moms Panel. I actually asked this very question to a Cast Member on my last stay at
Walt Disney World! When I checked in at the front desk, the Cast Member was able to attach my
Disney gift card to my resort reservation and
MagicBand, but I still was required to have a credit card on file. The MagicBand was able to charge beyond the gift card balance though and spending was not limited to that value. So if I spent $100 and my gift card was for $25, upon check out the gift card balance was used first and my credit card was charged $75.
You can set up which bands have the ability to charge when you customize them in your
My Disney Experience account or upon check in. Each time a charge is made on a MagicBand, you must enter a pin as well to prevent unauthorized charges.
I hope you and your family have a magical trip and please let us know if you have any more questions!
-Lindsey