In QuickBooks, there's no limit on how many payments or amount of payments you can receive via ACH transfers, @kelly178. However, your client has a possible limit for the money and transactions they can process per day.
Your client can check on their bank website or contact their bank to check how many transactions and amount of money they can process per day.
Check out these articles for more details about when QuickBooks deposits customer payments into your bank account: Find out when QuickBooks Payments deposits customer payments.
Also, visit this article for future reference in recording the payments via ACH bank transfer in QuickBooks: Receive and process payments.
Comment below if you need more help managing customer payments or other QuickBooks-related concerns. We're always here to help.