How do I permanently add a rep code to a customer?

Thanks for joining us here, @rochelle-ltplast.

I'll share some information about adding a rep code to a customer's profile. Currently, the option to add the rep code to a customer's file isn't available. You'll need to manually enter the rep code each time you create a transaction. See the image below.

Learn more about adding fields in this article: Customise invoices, quotes, and sales receipts in QuickBooks Online.

I'm also attaching this link here if you need help in managing customer-related tasks: Sales and customers.

If you still have questions or concerns with customers, please let me know. I'll be here for you. Take care and have a nice day ahead.