Time tracking for consultants and agencies: bill every hour accurately
Last updated: July 2026
Consulting and agency work punishes sloppy time tracking twice: once when unbilled hours quietly vanish, and again when a client questions an invoice you cannot back up with a clear record. The job is a constant switch between clients, projects, calls and internal work — exactly the pattern a single start-stop timer handles worst. This guide is a practical way to capture all of it accurately and turn it into per-client reports and invoices you can defend.
Why consulting time leaks
A consultant's day is not one task; it is a dozen. A client call, a review, two hours of focused work for one account, a quick fix for another, plus internal time — proposals, admin, learning — that no one pays for directly but that still has to be accounted for. Every switch is a moment to forget the timer, and every forgotten switch is either an unbilled hour or one attributed to the wrong client. Across a month those small leaks add up to real money and, worse, to invoices you cannot substantiate. The fix is a system that makes the right thing easy: capture as you go, attribute as you go, and review before you bill.
Structure first: clients, projects and rates
Accurate reporting starts with structure, not stopwatch discipline. Set up each client once, with the details that drive the invoice:
- An hourly rate per client — and, where an engagement differs, a rate per project that overrides it. Retainer, discovery and out-of-scope work rarely bill the same.
- A billing currency per client — so an international roster does not force you to convert by hand.
- A rounding rule — round up, down or to the nearest increment (say 15 minutes), set once per client and inherited by its projects.
With that in place, every hour you track already knows who it belongs to and what it is worth. In Døgn this lives under Clients & projects; the shape is the same in any serious tracker.
Billable vs internal, kept honest
Not every tracked hour is billable, and pretending otherwise is how you lose a client's trust. Mark internal work — proposals, admin, your own learning — as non-billable as you log it, so it stays visible for your own capacity planning without ever landing on an invoice. A good tracker keeps the raw captured time intact and only rounds the billed view, so your internal record stays exact while the client sees tidy increments. The payoff shows up in reporting: a per-client breakdown that separates billable from internal, and an effective hourly rate that tells you what an account actually earns once the unbilled time is counted. More on drawing the line in billable vs non-billable hours.
Track several engagements at once
Agency work is rarely one-at-a-time. You are running a build for one client while reviewing a pull request for another, or sitting on a retainer's support line while doing focused work elsewhere. A tracker that allows parallel timers lets each of those run on its own line instead of forcing you to stop one to start the next — and stop the right one when an engagement ends. The discipline that keeps this honest is simple: parallel timers are for genuinely concurrent attention, not a license to bill the same minute to two clients. The full rules are in parallel time tracking.
From tracked hours to a per-client invoice
Tracking only pays off if it becomes an invoice with almost no friction. At month's end you want time and earnings grouped by client for the chosen period, the internal share broken out, and the numbers ready to hand off — not an evening of copy-paste. Døgn does this two ways: a CSV export with a column for every field an accountant expects (date, client, project, description, notes, billable, start, end, rate, amount), and an HMAC-signed webhook that pushes finished entries straight to a draft invoice. See Reports for the per-client view. The point is not the tool; it is that the last mile — hours to document — should be a click, or your carefully tracked month rots into an estimate.
Questions, answered
What is the best way to track time across many clients?
Give each client its own rate, currency and rounding rule up front, then track against projects nested under them so every hour is attributed as you go. Review weekly and bill from a per-client report. Parallel timers help when you genuinely split attention across engagements.
Should agencies bill rounded time?
Many do — 15-minute increments are common and set client expectations cleanly. Choose a tracker that rounds only the billed view and keeps the raw captured time intact, so your internal records stay exact even when the invoice shows tidy increments.
How do I handle non-billable internal work?
Track it, but mark it non-billable so it never reaches an invoice. Keeping internal time visible lets you compute utilization and your effective hourly rate per client — the numbers that tell you which accounts are actually profitable.
Do I need cloud software to manage client time?
No. Cloud tools add team sync and shared dashboards, which larger agencies may want, but a solo consultant or small studio under NDA is often better served by a local tracker that keeps client names and project details off third-party servers. Døgn and Timing are local; Toggl and Harvest are cloud.