When the Mark Paid feature is used for a lump sum payment which pays off two or more invoices, it makes notations in the "Notes" area on the bottom of the Invoice Screen.  For instance, let's say a customer sends you a check for $80, and it pays off three invoices:  $40 for invoice 442475, $10 for invoice 442574, and $30 for invoice 442560.

When you use Mark Paid and record the $80 payment on invoice 442475, the following notation will appear in Notes: "This payment paid off the following invoices:   442575 442574 442560·"  The first number listed is always the number of the current invoice.  Thus, invoice # 442575 will be the current invoice, the invoice on which the payment is recorded.  The next invoices listed  (442474 and 442560) are the other two invoices the payment pays off.  In the Notes area of invoices 442474 and 442560, the Mark Paid feature will print the following: "Paid on invoice number:  442575."

The notations give you a record of invoice payments. It's important not to change or alter the notations, invoice numbers, or the end marker. The end marker is a small dot (·) placed immediately at the end of a list of invoices in Notes on the invoice where the payment is recorded, and it is used by the Mark Paid and Payment Analysis function to signal the end of a list. (The small dot is a CHR(250) character, created by pressing ALT and typing 250 on the numeric key pad).  The notations, invoice numbers and end markers are all important for determining what has been paid and what hasn't.  It's fine to type notes to yourself before or after the notations, just remember not to erase the notation or change it in any way.  If you've made a mistake and have marked an invoice paid that shouldn't be, use the Remove Payment Status option which will remove the notation automatically for you.

The Mark Paid feature also prints a status message in the "Payment" area of the invoice.  Status messages include "Status: PAID,"  "CREDIT," "REFUND ISSUED," etc.  For a description of each of the status messages, see Parts of the Invoice Screen: Payment Box.