How to track the un matched PO?

Hi Experts,

 

Is there any way or any query through which we can analyze which PO’s which are called while creating the Invoice but not matched with the PO’s and after that manually enter the distribution of it and pays the Invoice?

 

Because of it our accruals are still there in the AP Accrual Account and if user enters the manual Invoice and only calls the PO but not press the button of matched and then manually enters distribution and in that distribution gives the AP Accrual account then what happen?

 

 

Thanks in Advance.