How to void a bill in a closed period
An unpaid bill, that needs to be removed, normally can be deleted. If the bill is in a closed period, you will only have the option to void the bill. Voiding a bill will create a journal entry reversing the original transaction.
The software will not allow a void date prior to the current accounting period. To get the void date to be the same as the original bill date, void the bill in the current period then edit the voiding journal entry date to the date of the original bill.