Glossary
Billable hours
Billable hours are the hours an employee spends working on tasks that can be directly charged to a client. They are the primary mechanism through which most agencies and consultancies convert labour into revenue. Accurately tracking billable hours is essential to invoicing clients correctly, understanding project profitability, and managing team utilization.
Billable vs non-billable hours
Not all working hours are billable. Non-billable hours include internal meetings, business development, training, administrative tasks, and internal projects. For most agencies, non-billable time accounts for 20-35% of total working hours.
The split between billable and non-billable time is one of the most important ratios for agency financial health. Too much non-billable time drives down profitability. Too little may signal the team is not investing enough in internal quality, training, or growth.
How billable hours are tracked
Time tracking tools allow employees to log hours against specific projects and tasks throughout the day. Some agencies use timers that run in real time; others prefer end-of-day or end-of-week manual entry. The more granular the logging, the more useful the data for both invoicing and project analysis.
Billable hours should always be logged against a client project with a clear task description. This makes it straightforward to generate accurate invoices and to analyse which tasks are consuming the most time relative to budget.
Billable hours and project profitability
Billable hours are the main input to understanding whether a project is on budget. When you track hours in real time against a project budget, you can see at any point what percentage of the budget has been consumed and whether delivery is on track.
On fixed-fee projects, billable hours tell you the actual cost of delivery against the fixed revenue. On time-and-materials projects, they feed directly into the invoice. Either way, the data is essential for measuring margin and identifying over-servicing early.
Common problems with billable hour tracking
The biggest issue most agencies face is inconsistent or delayed time logging. When people log time at the end of the week rather than in real time, they forget short tasks and round numbers, which distorts project data and makes invoices less accurate.
Another common issue is misclassifying non-billable time as billable (inflating invoices) or vice versa (undercharging clients). Clear policies about what counts as billable and good tooling to make correct logging easy are the main mitigations.
Example
A project manager spends 4 hours reviewing client deliverables, 2 hours on a client call, and 1.5 hours updating the project plan. These 7.5 hours are billable. They also spend 45 minutes on an internal team meeting and 1 hour on a proposal for a new prospect. Those 1.75 hours are non-billable. For the day, their billable percentage is 81%.