To clear old WIP complete the following steps:
Create a new Fee Batch.
Ensure the checkbox to include matters with zero wip is selected.
Launch the Allocation details screen
Highlight the matter line
Right click and select Allocation Details.
Enter the offsetting fee or write off amounts.
The fee screen will appear the same as it did prior to accessing the allocation details.
Click on the X button to close the Allocation Details screen.
Save the changes.
Post the fee. When prompted with the message This will create a debtor transaction with a $0 total, select No.