Thanks for joining this conversation, @springcpa.
When you register for a Merchant Services account in QuickBooks Desktop, the processing fees vary a little depending on whether you decide to pay as you go or pay monthly. If your customer chooses to pay an invoice with their card, the fee would be 3.5% + 30¢ (pay as you go), or 3.3% + 30¢ (monthly).
If you want to change processing fees, I highly suggest contacting our Merchant Support team. They're able to pull up your account in a secure environment and discuss this further.
To reach them, refer to this article and proceed to QuickBooks Desktop with Payments section to get their most updated contact information: Contact Payments Support.
To learn more about the accepting customer credit card payments, consider checking out this article: Payments for QuickBooks Desktop.
I want to make sure everything is taken care of for you, so let me know if you have any other issues or concerns by leaving a comment. I'm always happy to help. Have a great weekend!