This is a very simple but powerful utility that merges two existing customers into one customer. The intended usage of this utility is for scenarios in which a customer has been added to, and used in, your database. If you have a duplicate customer, but the customer hasn't been used in any transactions, you can simply delete it. However, if it has been used (in a sales order, for example) you will need to use this utility to remove this duplicate from your system.
Just provide the customer account number that you wish to keep and the customer account number you wish to remove. The system will then make sure that every database row that references the removed customer will be updated to now reference the customer being kept. Once all of the rows are updated, the system will delete the customer you want removed.