This is specifically relevant to projects where billing is based on hourly rates. Currently it is possible to amend the hourly rate but this then affects historic data in the timesheet overview  (such as logged hours x hourly rate) which makes changing the hourly rate difficult.

A work-around is to bill using "hours by task" but it's a tedious when there are lots of projects with even more tasks. Additionally, the same task name cannot be repeated for any given project and it distorts reporting.

I'm not sure I'm posting this in the right category but I couldn't find a "feature request" category :)