First, check to see if the header section or the receipt section needs the correction.
This article will help you determine which is the header and which is the receipt: Is My Header or My Receipt Wrong?
On the Options Menu, click Headers. On the PAYLEX Invoice Header, begin typing the invoice number.
Highlight the correct invoice and click Change.
Make the appropriate changes to the Tot_Pay and Balance field and click OK.
The change can be seen on the main screen.