Good day, Answer2019.

Helping you change the customer's profile is my priority. Let's get this set up.

To change the customer's profile into Nan-Taxable, you can set a default 0% for the tax code for your tax-exempt customer. You will first need to create a Non-Taxable item and assign it to your customer.

Here's how:

1. Click Lists at the top menu bar then choose Item List.
2. Press Ctrl+N to create a new item.
3. Choose Sales Tax Item as the Type.
4. Set the Tax Rate as 0%.
5. Select Tax Agency and hit OK.

After that, you can assign the item to the customer's profile. See the steps below:

1. Click Customers at the top menu bar and choose Customer Center.
2. Double-click the customer's name to edit.
3. Go to the Sales Tax Settings.
4. Select the Non-Taxable for Tax Code.
5. For Tax Item, choose Non-Taxable as well.
6. Hit OK.

Even if you assign a taxable item for the tax-exempt customer, it won't calculate since the tax code sets for them is 0%.

You can get more details in this article: Set up sales tax in QuickBooks Desktop.

Let me know how it goes by leaving a reply below. I'll stick around if you need more help. Have a good one.