Let me walk you through the steps on how to enter a vendor credit in QuickBooks Online. To do so, here's how:
Go to + New.
Under Vendor, select Vendor credit.
In the Vendor dropdown, choose your vendor.
Enter the Category or Item details depending on how you record purchases with this vendor. Usually, this is the category, product, or service you’re getting credit for.
Hit Save and Close.
After following the steps mentioned, you will be able to enter your vendor credit successfully.