How to add a manual cost to a task
Start on the tasks tab or full list.
Click the goto button for the task you want to manually at a costing for.
On the task record select the options tab and the option 1 costs & duration sub-tab (these are usually pre-selected by default).
On this tab, enter:
NOTE: You can force a re-lookup of the relevant quantity/area and the unit of measure from the linked resource/object by clicking the re-lookup quantity button (1)
When you manually enter a task cost, you will see this dialog.
Click Yes to proceed.
The rate (1) for the task will be adjusted, the rate type will be set to 'manual entry' (2) and the date and time when it was updated (3) will be set.
The source field (4) will show the user name of the current user