It's great to see you here today, @paracleteconsult.
The error message happens when the customer's name already exists in the file. That's why you're unable to locate the customer from the list when creating a new invoice.
To help fix this, let's change the display name from the Customers tab. Let me guide you how.
- Go to Sales from the left menu.
- Select Customers.
- Find the duplicate customer, and select the name to open the profile.
- Choose Edit.
- In the Display name as field, add a digit at the end of the name.
- Click Save.
The screenshot below shows you the last two steps. For detailed instructions, see the Change the display name section through this article: The Name Supplied Already Exists Error.
![ChangeCustomerDisplayName.PNG ChangeCustomerDisplayName.PNG](https://quickbooks.intuit.com/learn-support/image/serverpage/image-id/35269iFB27426D208136B5/image-size/large?v=v2&px=999)
If you no longer need the duplicate customer, you can make it inactive. This way, the system will allow you to add an identical name when recreating the customer. Then, create a new invoice for him.
Once your customer pays the invoice, use the Receive payment feature to record the payment. Just go to the + New button from the left menu. For more details, check out this article: Receive Invoice Payments.
I'm always here to help if there's anything else you need. Have a good day, @paracleteconsult.