In the Point of Sale,
  • Open the estimate,
  • Click on the spy glass, near the customer name,
 
 
 
 
  • In the Customer Maintenance window, click on the spy glass (with the eye) at the bottom to show all the customers,
 
 
 
 
  • Search for the correct customer of the invoice and double-click on it,
 
 
 
 
  • Click No to the question box: Do you want to create a new order?,
 
 
 
 
  • Click Yes to the question box: Do you wish to change the customer for this order?
 
 
 
 
If the new customer has other estimates, the system will ask you: Do you wish to display them? Click No.
 
  • And you have successfully changed the invoice order!