It's a pleasure to have you here in the Community, @Gambit. Allow me to assist you with this and help you with the admin fees for your contractors.
To begin with, you can add the admin fees for your next payment on the sub-contractors in QuickBooks Desktop (QBDT). Then, create a service item or account for the admin fees and add it when generating a check or direct deposit. Please ensure that the amount is negative so it will be less than the total payment.
Here's a quick guide on how:
1. Go to Lists and select Item List.
2. Click on Item then New.
3. Choose Service as the type of item.
4. Fill out the item details, including a negative amount for admin fees.
5. Save the item to use when creating checks or direct deposits.
To learn more about handling your chargebacks, I've added this helpful resource: Handle chargebacks and retrieval requests for QuickBooks Payments.
Furthermore, I'd also suggest consulting your accountant when creating a service item or account to avoid any discrepancies with your financial records.
I'm just a few clicks away if you have additional queries about handling admin fees. It would be my pleasure again to assist you in any way I can.