To write off a time entry before you create an invoice, navigate to the Work In Progress tab within the Matter Details window for a particular matter. This is where all your time entries are listed.
Click on the time entry you would like to write off so it is highlighted, and then from the Extras Section in the Top Toolbar click on Write off Work in Progress.
A window will open allowing you to confirm that you want to write off the selected time entry. You can also choose to partially write off the time entry.
Click on Save to confirm you would like to proceed.