I paid a bill by mistake in the system and need to have it unpaid is this possible?

Thanks for giving QuickBooks the opportunity to serve you with your accounting needs, @the4tutts.

I've got you covered in deleting the payment that you've mistakenly applied. 

This can be done by selecting the delete button from the payment that you made. Let me guide you how:

1. Go to the Expenses tab on the left pane.
2. Choose Vendors.
3. Look for the vendors' name.
4. Locate and open the bill payment that you made.
5. On the bill payment screen, click on the More at the bottom.
6. Select on Delete.

From there, the bill will now show as unpaid. That it, the4tutts.

Here are some tutorials and articles that you can check out to help you with running QuickBooks:

• All QuickBooks Tutorials
• Help Articles for QuickBooks Online. 

You can always find me here if there anything else you need with QuickBooks. It's my pleasure to help. Have a fantastic weekend!