Error 3100: " Error:The name "John Smith" of the list element is already in use."

A helpful overview of how to handle multiple customers with the same name, as QuickBooks does not allow the exact same name to be used for multiple customers.

Written by the MyWorks Team

Updated at June 30th, 2023

Table of Contents

Are you seeing this error when syncing a custom or order into QuickBooks Desktop using MyWorks Sync?


Error: 3100:

" Error:The name "John Smith" of the list element is already in use."


Troubleshooting Steps

This error can occur if the customer name in the WooCommerce order is already being used in QuickBooks Desktop by a vendor, employee, or inactive customer. If MyWorks can't find a customer with this name in QuickBooks, it will attempt to create a new customer; but the error above can occur if QuickBooks rejects that new customer if the name is already taken in QuickBooks by a vendor, employee, or inactive customer. 

Note: MyWorks will already be able to identify if an existing customer name is in QuickBooks, and correctly sync the order to either that customer, or a new customer. However, the above error can occur if the name is being used outside of the customer list in QuickBooks - like a vendor or employee.

However, this can be easy to resolve:

  • In QuickBooks, open the Customer Center > Customer List. Does this customer name already exist in QuickBooks? (in most cases it will not). If it does, simply refreshing your list of customers in MyWorks Sync > Refresh Data should then allow the order to sync to QuickBooks successfully.

  • Check your list of vendors and employees in QuickBooks. If this name exists there, that's why the above error is occurring, since QuickBooks doesn't allow customers, vendors and employees to have the same names. Slightly adjusting the vendor/employee name in QuickBooks to be unique would allow the order to then sync in!

  • Still can't find this name anywhere in QuickBooks? Try either manually creating a customer in QuickBooks with this name (which should result in the same error from QuickBooks when you attempt to save it) - or, check your inactive customers, vendors, or employees for this name.
  • Still can't figure it out? Open a support ticket with our team, and we can help jump in to see what might be occurring.