Hey there, sevans.

Let me help you with pay an invoice to reduce the vendor bill in QuickBooks Desktop.

A barter bank account is used to post both sides of a traded transaction. For instance, you might trade or exchange something you sell for something a client sells. Recording a barter transaction in QuickBooks is a process that requires a few one-time setup steps that can then be used to record any barter or trade transaction you may have with your customers or vendors.

Make sure that the barter's partner name is both listed as a vendor and a customer. For example, you can either use Intuit Smith as the customer name and then Intuit L. Smith as the vendor name.

To set up a barter bank account:

1. Click List at the top menu bar, then choose Chart of Accounts.
2. Press CTRL+N on your keyboard to create a new account.
3. Choose Bank and hit Continue.
4. You can enter Barter Bank Account as the name and click Save.

To create an invoice for the barter transaction:

1. Customers at the top menu bar and select Create Invoice.
2. Fill out the invoice as you normally would and then Save it.
3. Customers at the top menu bar and select Receive Payments.
4. Choose the barter Customer.
5. From the Payment Method drop-down menu, select Add New and then enter "Barter" in the name field.
6. Choose Save.
7. Select Deposit To: choose the barter bank account.
8. Hit Save.

To enter a bill for a barter transaction:

1. Click Vendors at the top menu bar and select Enter Bills.
2. Fill out the bill as you normally would and then Save it.
3. Click Vendors at the top menu bar and select Pay Bills.
4. From the Payment Account drop-down menu, select the barter bank account.
5. Select the bill you want to pay
6. Enter the amount of the bill payment and then hit Save.

By following these steps, you'll be able to pay the invoice and reduce the vendor bill.

Let me know if you have additional questions about reducing vendor bills. I'm always here to help.