What is the easiest way to reduce the employee hours on a completed and billed project? Is there a way to enter negative hours?
In case of billed time entries, you can reverse the invoice, write down the time and then recreate the invoice. Check the Core Help for details.
Core allows you to enter negative time (and expenses). However, it’s recommended to write down time instead so that Core can report exactly how much was written down per invoice. You can also apply discount in the Invoices screen to reduce the service amount.
If you enter negative time to offset the billed time, one down side to it is that Core will not clear them from your WIP report and over a period of time, they will simply make your WIP report messy. You may want to flag the incorrect and negative hours as non-billable and then mark them as billed to clear your WIP.