how do i record a minus expense when i return a purchase

In QuickBooks Online, you can record an expense credit in three ways, based on how the purchase was initially recorded and how the vendor is returning the money. If you receive a credit and plan to apply it to future payments, create a supplier credit and apply it to a bill.

Here’s how:

1. Go to +Create and select Supplier credit.
2. From the Supplier dropdown, select the supplier.
3. Enter the Category details or Item details for the credit as needed.
4. Select Save and close.
    

After that, apply the credit to a bill.
 

1. Click on the +Create and choose Pay bills.
2. Select the bill you want to pay.
3. Verify the Credit Applied amount.
4. Select Save and close.

If the supplier sends you a refund, follow options 1 and 3 in this article: Enter supplier credits and refunds in QuickBooks Online.

Feel free to reply if you have other concerns. I'm always here to help.