Welcome to the Community. It's essential that you know the details about the fees charged for using E-pay service in order to keep track of your books. QuickBooks Online is a flexible program that simplifies the way you manage your books. I'd be glad to provide information on the online payment option in QuickBooks.
QuickBooks Online offers the ability to receive online payments from your customers by sending them invoices from the program. When using the payments feature, you'll be automatically charged per transaction at a rate of 2.9% plus $0.25 per transaction.
I'd encourage you to review the following articles regarding QuickBooks Online Payment.