If users want to restrict available accounts to only bank accounts on the Account field of Accept Customer Payments screen (Transactions > Customers > Accept Customer Payments), kindly follow the steps below:
1. Using an Administrator role, navigate to Setup > Accounting > Accounting Preferences.
2. On the General tab > General Ledger portlet > Expand Account Lists = Uncheck/False.
3. Click on Save.
There is already an Enhancement request to have a separate preference for this.
Enhancement 78549 - Accept Customer Payment > Allow users the option to restrict available accounts to only bank accounts.