It's a pleasure to have you here, @Sam H.
To set up or create an account for vendors who are also the customer is to slightly make a different name to indicate its customer/vendor profile.
You can visit this link to view suggestions: https://quickbooks.intuit.com/learn-support/en-us/reports-and-accounting/re-make-a-customer-a-vendor...
Additionally, you can also visit our Support page if you need more tips, resources, and video tutorials. It includes information to help you manage your company files.
Don’t hold back to add a remark below if you need further assistance with managing your customer and vendor lists in QuickBooks. I’m here to help always. Keep safe and take care.
Good to have you back, and I'd like to show you the process of dealing with the sold copier and the advertising bill from the same entity.
You would want to set up a barter transaction for the copier sold and the advertising bill. Generally, you'll want to create a barter account, a bill (for the advertising bill), and an invoice (for the copier sold).
Create a barter account:
If you haven't done it yet, create a customer account for the vendor. Then, create their vendor profile afterwards.
You can add something to differentiate between the two profiles such as John Doe-Vendor or John Doe-Customer (QuickBooks won't let you create lists with the same name).
After creating their profiles, enter an invoice for the copier sold:
Then, enter a bill for the advertising:
To initiate the barter transaction, simply create a payment for the invoice then deposit the funds to the barter account you've created. Go to the Customers menu, then select Receive Payments.
If you don't see the Deposit To drop-down menu, QuickBooks sets Undeposited Funds as your depositing account. Create a bank deposit by going to Banking, then selecting Make Deposits.
Alternatively, you can unset the Undeposited Funds account as your main destination by editing your preferences:
Finally, create a bill payment using the barter account's funds:
You'll want to keep creating the payments until the invoice and bill amounts offset each other.
That covers on how you can handle the copier sold and the advertising materials for a vendor who is also a customer.
If you need a guide on how to run reports to see your transaction data, you can check this article: Understand reports.
You're more than welcome to ask any other questions in recording your transactions. Do you have any other concerns about your lists, reports and other data in QuickBooks? Let me know and I'll throw in some guides for you.