I can provide information when managing customer payments and processing fees in QuickBooks Online, info2052.
For QuickBooks Online Payment pricing, all ACH transactions are charged at a 1% fee with a maximum of $10 per entry.
Processing fees also vary depending on whether the card is swiped (2.4%), invoiced (2.9%), or keyed (3.4%) and on the amount of payment being processed. I've included a screenshot below for reference.
You can also request a rate review for your company to get a discounted rate when processing transactions. To see how you qualify and meet the requirements, check out this article for more details: Request A Rate Review of QuickBooks Payments Discount Fees.
Furthermore, here's a reference you can utilize to help you process ACH payments and understand when QuickBooks deposits them into your bank account:
If there's anything else you require additional assistance with managing customer payments and processing fees, let me know in the comments below. Stay safe!