How to enter and match the refund from vendor?

Hi there, @Kateryna_G.

I'd be glad to help you how to enter a refund transaction from your suppliers in QuickBooks Online (QBO).

You can create a Deposit, Supplier credit, and a Bill transaction to link it. This is done to avoid getting a negative balance on your supplier's account in QBO. Then, match it in the Banking page. I'd be glad to show you how to do that:

1. Select the + New button and choose Bank Deposit.
2. In the Account field, select the account where the money will be deposited.
3. Enter the rest of the refund details.
4. Click Save and Close.

Then, create a Supplier credit transaction. Please see the steps below:

1. Select the + New button and choose Supplier credit.
2. Enter the refund details, ensure that the amount is correct.
3. Select Save and close.

Once done, you'll need to create a Bill. Then, link the Supplier credit and Bill by creating a Cheque transaction. You can follow the steps below:

1. Click the + New button, select Cheque.
2. Enter the supplier's name.
3. There will be a pop-up window on the right pane, select Add to the Supplier credit and the Bill transaction that you've made.
4. Verify the details and select Save and close.

Now that the check and the credit have been linked, it's time to match it on the Banking page. Here's how:

1. Go to the Transactions menu, select Banking.
2. Click the tile of the bank account where the supplier sent the refund.
3. Select the For Review tab and look for the match. Note: QuickBooks will automatically detect the matched information. 
4. Click on the transaction, verify the details, and select Match.

I've added this article for your future task when you're ready to assess your business financials with QuickBooks: Reconcile an account in QuickBooks Online. This contains how you can undo or fix errors in case you bump into one.

I'll be here if you have other questions. Let me know in the comment section and I'll be here to assist. Take care.