The following GL Entry is created when a Payment on an Invoice is Posted:
CR - Asset Account: Accounts Receivable - Customer Sub Account
The amount for the journal entry is calculated by the Pricing Policies for the product. If there are multiple line items on the Invoice, the above journal is created for each product.
The Receive Payment screen allows you to select the Receive to Account.
The default Accounts Receivable account has sub-accounts for each customer.