I am trying to apply a vendor credit and each time I click vendor credit it takes me to the Quickbooks upgrade screen. Do I need to upgrade for this service?

Thanks for sharing your concern here in the Community, @neffsglellc.

I want to share some clarifications regarding the upgrade screen that shows up upon applying vendor credits in QuickBooks Online.

Managing vendors' transactions like applying credits work best for the higher version of QuickBooks such as Essential, Plus, and Advanced. If you're using the Simple Start version, I recommend upgrading your account so you can apply vendor credits.

To do that:

1. Hit on the New button at the left pane.
2. Select upgrade arrow beside Bills.
3. On the QuickBooks versions page, choose Essentials and tick Upgrade button.
4. From the subscription page, verify your payment details then put a check-mark on the authorization box.
5. Press on Change Plan.

I've outlined these steps below for your reference:

On the other hand, if you're subscribed to the higher version already, I recommend accessing your account using a private window. This mode prevents the system from using stored internet history, passwords, or cookies. 

Know that unexpected behaviors while working with QBO can be caused by corrupted files on your browser. 

Here are the shortcut keys for each browser:

• Press Ctrl + Shift + N for Google Chrome
• Hit Ctrl + Shift + P for Internet Explorer or Mozilla Firefox
• Hold Command + Shift + N for Safari

If the upgrade screen is no longer showing up, clear the cache on the browser you previously used. This enhances the overall performance of the browser and the application. Using other supported browsers is a good alternative too.

I also suggest running the Health Checkup Tool. This checks your browser's performance and it's compatibility with QBO. 

Once done, you can now start with applying vendor credits in the system. 

To do that:

1. Select + New.
2. Press on Pay bills or Pay bill.
3. Choose a bill for your vendor from the list. You'll see the available credit with this vendor in the Credit Applied field.
4. Complete the rest of the fields like you normally do.

I got here a link that you can scan through to learn more about managing your vendor's credit in QBO: Enter a credit from a vendor.

Let me know if you have any other questions on this. I'll make sure you're taken care of. Have a wonderful week ahead!