Project management that ends in an invoice
Work tracked in one tool and billed from another is work that goes unbilled. NikProjects keeps tasks, time and expenses against the project and raises the invoice from them.
Time and expenses against the job
Timesheets and expenses sit on the project, so the margin on it is visible while it is running rather than after it closes.
Milestone and time billing
Bill a fixed milestone, bill the hours, or bill both — as a proper GST invoice from the same system that tracks the work.