My customers are repeat customers. When they pay via bank transfer, can they keep their bank account info on file so they don't have to always re-enter?

 This is one of the payment methods that are fast and secure, Steph15. 

We're unable to save their bank information, though. The customer will have to re-enter once they pay through bank transfer.

I know it's convenient on your part and as well as the customer's to easily pay the sales transaction without re-entering their info. I'll take note of your concern and submit it to our management team. This will be forwarded to our software developers for assessment. 

I'll share this reference regarding the common questions about payments deposits in QuickBooks Online. 

Feel free to reach out to us if you have other payments concerns. 

@steph15 

Explore this payment service. It accepts reccuring ACH/direct debit.

http://get.practiceignition.com/quickbooks

Hope it helps.