In some versions, the energy consumption screen can be edit after a job is invoiced.
How to edit energy consumption for an invoiced job:
On a record's energy consumption screen you will see a button called "Edit Energy Consumption." Select this and you will be able to change the information on the energy consumption screen.
You will know if your version has this feature by going to the Roles screen, editing a role and clicking the Client menu tab and Energy Consumption. Set the Features field to Fuel Usage Detail and you will see the option to check Edit Energy Consumption.