Here is a guide on merging or changing customer information.
Merge Customer Codes
Before you start, you will need to have two customers in mind that you want to merge together: one with old data that will be overwritten (Customer A) in part and one with new data (Customer B). Any data from Customer A in fields that are empty in Customer B will be moved during the merge. Any data from Customer A in fields that are not empty in Customer B will be overwritten.
In ERP, go to Utility > Merge Customer Code.
Enter the Customer # you want to merge from (Customer A) in the Customer # From field. You can also use the magnifying glass to search. Enter the Customer # you want to merge to (Customer B) in the Customer # To field. Click Apply.
A notification will appear telling you the merge was successful.
Change Customer Codes
The first thing to note is that it is not possible to change the Customer Code from Customer Management.
In ERP, go to Utility > Change Customer Code.
Enter the original Customer # in the Customer # From field. You can also use the magnifying glass to search. Type the new Customer # - the one you want to change it to - in the Customer # To field. Click Apply.
A notification will appear telling you the change was successful.
Note: When you merge or change customer codes, this will retroactively update all existing Sales Orders and Invoices associated with the original customer # to the new one.
Warning: Once done, this action cannot be undone.