Great job in exporting your customer list, R Mouer.

I'm here to guide you on how to import your data to your QuickBooks Desktop (QBDT) 2021.

Only company files can be imported when using QBLauncher. To seamlessly import your customer list, you'll want to go to the File menu and upload the file from there. Let me show you how.

If you've exported your customer list via MS Excel, you can follow these steps in importing it:
 

1. Go to the File menu.
2. Select Utilities then Import.
3. Then select Excel Files.
4. If you get the Add/Edit Multiple List Entries window, click No.
5. Follow the wizard in importing files.

You can also check this link for more details: Import or export MS Excel files.

However, if you've exported it as IIF file and received an error, you can refer to the troubleshooting steps provided in this link: Improved IIF Import in QuickBooks 2019 and later.

You can also read this article for more insights about importing and exporting data in QBDT: Import and export data in QuickBooks Desktop.

Let me also add this resource that you can utilize in case you need to merge your accounts and customers: Merge list entries in QuickBooks Desktop.

I'll be around if you have other concerns about importing data in QBDT. Have a great week ahead!