Hi Lenora!
Welcome to the Disney Parks Moms Panel! We're so glad that you found us hEAR! I don't have the proper Magic Mirror to see exactly how your upcoming Walt Disney World
Resort Hotel Reservation is set up, but I have two guesses, as well as another solution.
Sometimes when families or friend groups are split into multiple guest rooms, each is booked as its own resort reservation controlled/accessed only by those staying in each respective room. This is so things like
Disney Dining Plan entitlements or MagicBand charges have less of a chance of getting mixed up between everyone in the party, and also so those in room one can't gain access to room two on their own. If you have two resort hotel reservation confirmation numbers, then yes, your nephew should be able to link his separate booking to his
My Disney Experience profile and then
pay his individual balance online.
If, however, you do have two rooms within one reservation confirmation number, then the pre-vacation balance amount of both rooms will be lumped together and only one of you, and only one credit card at a time, can be the "primary" on the account.
If the second is how your stay is set up, something that he can do is call a payment in. As long as he has the confirmation number and is a named guest in one of the rooms, he can absolutely pay his portion with a credit card, debit card or even a (or multiple)
Disney Gift Card over the phone. This phone number is (407) 939-7675.
Bonus Tip: Circling back to
MagicBand charges. No matter how your two rooms are booked, he'll be able to connect his credit card to his MagicBand. This way anything he charges, from a
Dole Whip to a
Droid, will hit his method of payment and not yours. If you do have two separate reservations, he'll be all set the moment he arrives. But if your two rooms are together in the same booking, he'll need to visit the Front Desk of your resort hotel to take care of this. It's a quick, under 5-minute process. All he'll need is his MagicBand, credit card, and photo ID.
I hope this helped to clEAR things up a bit, Lenora, and We'll See You Real Soon!
~Kristen