Hello Andrew
Are you using QuickBooks Online?If so there is not a report that shows this.You can edit a transaction list by supplier report and customise it using the customise in the top right>rows and columns>change columns>add a tick in Tax amount and A/P paid>select the filter>drop down by A/P paid>select unpaid>run report
You can do the same for the transaction list by customer report.
Any further questions or if you are using the desktop product just reply back to this post
Emma