Time and Materials (T&M)

Time and materials (T&M) is a billing model where you charge the client for the actual hours you spend on their project at an agreed hourly (or daily) rate, plus any out-of-pocket expenses. The final project cost isn't fixed upfront — it depends on how much time the work actually takes.

T&M works best when project scope is uncertain or likely to evolve. Software development, research projects, and ongoing advisory engagements are natural fits. The client gets flexibility to change direction without renegotiating a fixed-price contract. You get paid for every hour you work, regardless of scope changes.

The downside: T&M creates budget uncertainty for the client. They don't know the final cost until the project is done. Mitigate this with a "not-to-exceed" cap — "estimated 120 hours at ₹3,000/hour, not to exceed ₹4,00,000 without prior approval." This gives both sides a ceiling.

T&M requires rigorous time tracking. Log your hours daily, categorize them by task, and share regular timesheets with the client. Disputes almost always arise from unclear or infrequent time reporting. Weekly timesheet submissions are the minimum standard.

Invoice on a regular schedule — biweekly or monthly — rather than at project end. This keeps cash flowing and avoids a single large invoice that the client might push back on. Include a detailed time log with each invoice showing dates, tasks, and hours.