Navigate to the customer record you would like to keep as the main customer record.
In the address bar of your browser, copy the customer ID portion to your clipboard.
Navigate to the customer record you'd like to delete.
Select Merge Customer from the menu.
When prompted, paste the ID you copied in Step 2.
What does the merge do?
If Customer A is the duplicate record, and Customer B is the valid record:
Customer A’s orders are assigned to Customer B.
Customer A’s club memberships are assigned to Customer B.
Customer A’s record is deleted.