How to Track Billable Hours and Profitability by Client

A client can look healthy on revenue and still drain margin every month. The usual leak is not one dramatic mistake; it is meetings, revisions, unbilled support, internal coordination and delivery overruns that never make it into the invoice.

That is why tracking billable hours by client is only the starting point. The useful system connects every hour to a client, project, task, person, billable rate, labour cost, budget and invoice status.

The aim is not to police every minute. It is to see which clients, services and project types create healthy margin before the month is over.

Start with the client P&L, not the timer

The right workflow starts with a lightweight client profit and loss view. A timer can tell you who worked on what, but it cannot explain margin unless the hours are tied to revenue and cost.

Billable hours by client are the invoiceable hours spent on each client. That metric helps with invoicing and resourcing, but it misses the work that weakens margin without appearing on a bill.

Non-billable client time matters just as much. Internal status calls, unbilled revisions, onboarding, reporting clean-up and account management all consume capacity, even when the client never sees a line item.

Delayed time entry makes the problem worse. Teamwork says delayed time entry can cause companies to lose 10–25% of billable hours, which is enough to distort pricing and profitability decisions.

The catch is cultural, not technical. If the team sees time tracking as admin, entries arrive late and vague. If they see it as margin evidence, the data becomes useful.

What metrics should you track by client?

Track seven metrics at a minimum: billable hours, non-billable hours, billable utilisation, effective hourly rate, direct labour cost, budget burn and client gross margin.

Billable utilisation is the share of working time that becomes billable client work. It is useful for capacity planning, but it can flatter a team if high utilisation is attached to low-margin fixed-fee work.

Effective hourly rate is client revenue divided by all client-related hours, including non-billable time. It is one of the clearest signals in an agency, because it exposes retainers that look fine until every meeting is counted.

Direct labour cost is total hours multiplied by internal cost rates. This should include employee or contractor cost assumptions, but it should not be confused with the rate you charge the client.

Client gross margin is revenue minus direct labour cost, pass-through costs and allocated overhead. AgencyPro gives the fuller margin formula as: Client Revenue minus Direct Costs minus Allocated Overhead, divided by Client Revenue.

Budget burn shows how much of an hourly estimate, fixed fee or retainer has already been consumed. It is most useful mid-month or mid-project; after delivery, it becomes a post-mortem.

How should you set up clients, projects and tasks?

Use a consistent hierarchy before anyone starts tracking: client, then project, then task or service line. If the structure changes every week, the reports will be noisy and project managers will stop trusting them.

Create one client record for every paying account. Under each client, split retainers, campaigns, builds and support into separate projects if they have different budgets or scopes.

Task categories should match how you sell and manage work. Common agency categories include strategy, design, development, copywriting, meetings, reporting, QA, account management and support.

Mark work as billable or non-billable at the task or time-entry level. A broad project-level label is easier to manage, but it hides the difference between invoiceable delivery and unbilled client servicing.

Set billable rates before invoicing begins. Depending on the tool, rates may sit at workspace, project, person, project-member or task level, so keep the rate structure simple enough for managers to maintain.

Store internal labour cost rates as well, where the software supports them. Revenue reports without cost rates show activity, not profit.

Decide which entries need notes. Notes are a slog if required for every five-minute task, but they are valuable for meetings, revisions, out-of-scope support and anything a client may question.

What formulas show whether a client is profitable?

Use the same formulas across hourly, fixed-fee and retainer work. Otherwise, hourly clients get measured properly while fixed-fee clients only reveal margin damage after delivery.

Billable amount equals billable hours multiplied by billable rate. For Time & Materials work, Harvest uses that basic model: tracked hours multiplied by billable rates.

Labour cost equals total hours multiplied by the internal cost rate. This includes billable and non-billable hours, because both consume capacity.

Client profit equals revenue minus direct labour cost, pass-through costs and allocated overhead. Profit margin percentage equals profit divided by revenue.

Effective hourly rate equals client revenue divided by all client-related hours. This is the number to use when a retainer feels busy but still looks profitable in headline revenue.

For a fixed-fee project, budget burn is the early warning system. If a £10,000 project has used 70% of its estimated hours by the halfway point, the margin problem is already visible.

What weekly workflow keeps margin visible?

Run the workflow weekly for active projects and monthly for retainers. Monthly-only reporting is cleaner, but it often arrives too late to fix scope creep.

First, check missing time. Late entries are the easiest way to underbill hourly clients and misread fixed-fee margin.

Second, review billable and non-billable hours by client. A client with high non-billable time may need a tighter scope, a paid support bucket or a reset on meeting cadence.

Third, compare budget burn with project progress. If 80% of the budget is gone and delivery is only half complete, the account needs attention before the next status call.

Fourth, compare invoiced revenue, uninvoiced billable time and non-billable time before month-end. This catches the common gap between work performed and work billed.

Finally, use the data to adjust pricing, staffing or client fit. The point is not a prettier report; it is a better decision while the decision still matters.

Which tool fits this job: Toggl Track, Harvest or Teamwork?

Toggl Track fits agencies that already manage projects elsewhere and need low-friction time capture. Its strength is that people are more likely to use it, but it will not replace a full delivery system.

Toggl Track’s Free plan supports time tracking for up to 5 users. Its paid pricing is recorded as Free, then $9, with Starter adding billable rates, project estimates and alerts, team reports, rounding, saved reports and tasks.

For deeper profitability work, Toggl Track’s Premium tier adds features such as profitability analysis, fixed-fee projects, labour costs, timesheet approvals and historical billable rates. The limitation is that the best margin features sit above the entry paid tier.

Harvest fits agencies that want time tracking, invoicing and online payments in one billing workflow. It supports Time & Materials, Fixed Fee and Non-Billable project types, but its strongest fit is billing from tracked time.

Harvest can calculate billable amounts from tracked hours and billable rates, with rates configured by project, person or task depending on setup. The buyer caution is that profitability reporting is positioned on Enterprise, and payment fees need checking before invoices go out.

Harvest supports online payments through Stripe and PayPal Standard. Stripe’s usual domestic US fees are listed in Harvest’s help content, but Harvest also says some accounts not on its Premium plan incur an additional Harvest fee shown during invoice creation rather than published as one fixed public rate.

Teamwork fits client-service teams that want time, projects, budgets, retainers, delivery and profitability in the same operating system. It is more than a timer, which is useful for delivery control but heavier if all you need is simple time capture.

Teamwork’s Free plan allows up to 5 projects and a maximum of 5 users, with time logging and work organised by client. Basics adds billable-time tracking and reporting, Accelerate adds retainers, time budgets and invoices from logged time, and Optimize adds revenue, cost and profitability insights.

The caution with Teamwork is plan clarity. Current plan names include Basics, Accelerate and Optimize, while older support content may still mention legacy plans; Teamwork also says usage-based AI credits are due to launch in September 2026.

How much does this setup cost?

For the tools covered here, the recorded starting prices are Toggl Track Free, then $9; Harvest Free, then $11; and Teamwork Free, then $10.99. Those numbers are useful for shortlisting, but the cheapest plan may not include the profitability features you need.

Toggl Track is the best fit if adoption is the main risk and your project system already works. The catch is that labour costs, fixed-fee projects and deeper profitability analysis are Premium or Enterprise-level capabilities.

Harvest is the stronger fit if tracked time needs to become an invoice with less manual work. The catch is that client and project profitability reporting sits on Enterprise, and payment-processing costs can affect what you keep.

Teamwork is the stronger fit if project delivery and profit visibility need to live together. The catch is that the richer budget, retainer and profitability features are further up the plan ladder, so a simple team may overbuy.

Free plans are useful for testing habits. They are rarely enough for a serious agency profitability system, because the key limits usually appear around users, projects, approvals, reporting, cost rates or billing workflows.

What mistakes make billable-hour reports useless?

The biggest mistake is tracking by person only. That helps with utilisation, but it does not show which clients or services create profit.

The second mistake is mixing billable and non-billable work in one bucket. It makes reports simpler, but it hides client-related drag and turns pricing decisions into guesswork.

The third mistake is using billable rates without labour cost rates. You can see revenue, but you cannot see whether senior staff are eroding margin on low-fee work.

The fourth mistake is treating retainers as guaranteed profit. Retainers only work if the effective hourly rate stays healthy after meetings, support and reporting are counted.

The fifth mistake is changing rates without preserving history. Toggl Track’s historical billable rates feature, available on Premium and Enterprise, exists for this reason: rate changes should not break past reporting.

The final mistake is waiting until the invoice is sent. Profitability should be reviewed before month-end, while scope, staffing and billing can still be corrected.

Turn the numbers into pricing decisions

The output of this system should be a short monthly client review. For each client, check revenue, billable hours, non-billable hours, effective hourly rate, labour cost, budget burn and margin.

Clients with strong revenue but weak margin need a decision. That may mean narrowing scope, raising price, charging for support, changing the delivery team or ending work that no longer fits.

Services need the same treatment. If strategy retains margin and reporting burns it, the answer is not always to work faster; it may be to price reporting differently or automate part of the process.

For a lean time layer, start with Toggl Track if the team needs a simple way to capture hours. For billing, choose Harvest if invoices and payments are the centre of the workflow. For agency delivery control, choose Teamwork if budgets, retainers and profitability need to sit beside project work.

The better the time data, the less emotional pricing becomes. You stop guessing which clients are worth keeping and start seeing which ones pay for the work they require.