Before associating invoices with sales orders, ensure that:
To associate invoices with sales orders:
Go to the Sales module on the left sidebar and select Invoices.
Select the invoices that you want to associate with sales orders and click Associate With Sales Orders at the top.
The invoices will be associated with the sales orders whose order numbers are specified in the respective invoice, and the status of the associated sales orders will be changed to Closed. You can view the details of the associated sales orders in the Associated Sales Orders section of the invoice’s Details page.
Online accounting software
for small businesses.