Hello, @Dixon FDS.

It's great to see that you're actively working to address the situation involving vendor A's outstanding AR invoice and AP invoice. You're definitely on the right track.

After creating the journal entry to transfer the AR and AP balances, you need to follow up with a couple of specific steps to ensure the offset is properly reflected and the transactions are accurately recorded. First, you need to set up a temporary bank account called "Clearing Account" to hold the offsetting amount. 

Then, follow these steps:

Apply the Credit to the Invoice: 

1. Click + New and then Receive payment.
2. Select your customer who's also a vendor.
3. In the Deposit to field, select the clearing account.
4. Keep the Amount Received field as zero.
5. Select the invoice.
6. Under the Outstanding Transaction section, select the checkbox for the journal entry. If you have automation to apply bill payments turned on, this step is done for you.
   
7. Select Save and close.

Pay the Bill: 

1. Click +New.
2. Select Pay Bills.
3. In the Payment Account field, select the clearing account.
4. Select a bill for your vendor from the list. You'll see the available credit with this vendor in the Credit Applied field.
   
5. Select Save and close.

By following these steps, you'll successfully offset the outstanding AR invoice against the AP invoice and then pay the net AP balance due to Vendor A. 

Furthermore, I recommend performing account reconciliations. This practice helps identify any disparities between your QuickBooks records and your bank statements. It serves as a valuable tool for detecting errors like duplicate or missing transactions, as well as incorrect amounts.

Feel free to reach out if you need any additional assistance or guidance. Best of luck with your financial transactions. I'm here to help if you need anything else.