How Sage 50 Applies The Payment Amount on Payments

If you enter a payment amount on the Payments screen, Sage 50 will apply the payment amount for you.

This is how it works:

Note: If you don't enter a payment amount, Sage 50 will calculate it based on the invoices you select to pay on the Apply to Invoices tab and/or the line items you enter on the Apply to Expenses tab.
If you are entering a payment to a customer and don't enter a payment amount, Sage 50 will calculate the payment amount based on the line items you enter on the Apply to Customer Account tab.