For marketing agencies and other professional services firms, time is quite literally money. Billable hours have to be accurately recorded and tracked to determine how much time was spent on a given client or project. That’s often easier said than done. Many teams juggle multiple clients and assignments, handling administrative work while shuffling assorted project tasks. When time isn’t properly recorded, client work can go unaccounted for, creating unbilled gaps that affect profitability. Understanding the mechanics, calculations, benefits, and challenges of tracking billable hours is the first step for businesses that want to build more reliable processes—and stronger revenue performance.

What Are Billable Hours?

Billable hours refer to the time spent performing client-facing work that generates revenue and can be charged to a client’s account at an agreed-upon rate. Billable hours are tracked and documented separately from total hours worked. Time spent on operational tasks, such as staff meetings, business development, and training, is generally considered overhead, and those costs are absorbed by the business. Marketing agencies, law firms, consulting companies, accounting firms, and engineering concerns are among the professional services businesses that use billable hours as a key revenue metric, making the accuracy of time capture and rate-setting essential to generating invoices, managing capacity, and establishing client trust.

Key Takeaways

  • Billable hours are the portion of a professional’s working time that can be invoiced directly to the client.
  • Logged billable hours help determine utilization rates, which is one of the most important metrics for tracking how teams, projects, or individual employees bring in revenue.
  • Most professional services firms use standardized time increments to record, review, and bill hours consistently.
  • Using time-tracking and accounting software helps companies avoid missed logs, duplicated entries, and other common sources of revenue leakage.

Billable Hours Explained

Billable hours tie effort straight to revenue and serve as the functional “inventory” of a professional services firm. When a team member logs time spent on a client project, those hours—multiplied by an agreed-upon hourly rate—become income. Since only a portion of any workday is billable, it’s important for companies to track time closely to assess how efficiently staff hours convert into revenue and cash flow. Time spent preparing a client presentation, drafting a contract, or troubleshooting a system for a customer typically qualifies; hours spent working on internal activities don’t.

This billing model also increases transparency, giving clients a clear sense of where their money is being spent and furnishing professional services firms with a defensible document for justifying fees. When applicable time goes untracked or is logged inaccurately, revenue leakage—in this case, caused by billable hours that are unbilled or underbilled—becomes a real and often hidden drain on profitability.

Data related to billable hours feeds many key performance indicators, including gross margin by project or client, which helps assess profitability; revenue per employee and utilization rates, both of which help develop staffing plans; and rate realization, which supports better pricing decisions. For most professional services firms, billable hours serve as a core operating measure, whether billed directly to clients or used as the underlying input for flat-fee or retainer-based engagements.

The Benefits of Tracking Billable Hours

For marketing agencies and other professional service firms, the benefits of tracking billable hours start with precise invoicing and extend into operational and financial areas when the data contributes to decision-making. When time capture is consistent, that knowledge supports businesses in the following ways:

  • Invoice accuracy: Documenting billable time as it happens or shortly thereafter guards against the risk of miscalculated hours and other common invoicing problems that create disputes and frustrate the client experience. Accurate time tracking supports itemized and defensible invoices that match the work performed, helping firms and agencies limit client pushback and revenue erosion.
  • Team performance optimization: A comprehensive—and accurate—log of billable hours can help leaders track where time is being spent across teams and assignments, spot potential bottlenecks or other inefficiencies, balance workloads and adjust staffing plans, and ultimately improve team performance companywide. Alleviating employee overextension by assigning someone else who has available bandwidth to the task at hand can prevent burnout and churn, especially in agency environments that are known to stretch available capacity. Studying the data also reveals which individuals or tasks are slowing delivery, which illuminates training needs and leads to more accurate scoping on future projects.
  • Profitability and budgeting: When billable hours are logged, businesses can assess whether individual projects—and clients—are actually profitable. Looking at historical data assists leadership in making future pricing and hiring decisions, understanding client budgets, and estimating scope for similar work in the future. Without this visibility, agencies may unknowingly overservice clients or undercharge for complex work.

Billable vs. Non-Billable Hours: What’s the Difference?

Not every hour worked is billable. When employees spend time on activities that are essential to support the business but can’t be charged directly to a client, those are called non-billable hours. Meetings and hands-on work on deliverables, such as design, strategy, campaigns, and reports, are the most straightforward examples of billable time. Depending on the specifics of each contract and how billable time is calculated, time spent on emails and calls related to active work, as well as travel to and from client sites, can also fall under the billable-hours umbrella.

Typical non-billable activities include the internal work required to operate and grow a business—internal team meetings, training and professional development, business development efforts (pitches, proposals), and administrative tasks (timekeeping, invoicing, HR activities). Since the line isn’t always clear, defining these billing parameters in engagement letters or statements of work can be beneficial to clients and professional services firms alike. For perspective, according to Promethean Research’s “2025 Digital Agency Industry Report,” the average agency employee is expected to bill 25 hours per week and spend another 13 hours per week on non-billable tasks—a roughly 65% billable ratio.

How Are Billable Hours Calculated?

At its simplest, billable revenue is calculated by computing the time spent on billable tasks for a client and multiplying the number by the hourly rate agreed on for each role or task:

Billable revenue = Billable hours × Hourly rate

For example, if a consultant works 25 billable hours at a rate of $150 per hour, the billable amount for that period is $3,750.

Most projects involve multiple contributors and tasks with different billing rates. In those cases, billable revenue is calculated by role or individual and then totaled at the project level. Adding a junior strategist to this project at $100 per hour for 15 billable hours would bring the total billable revenue to $5,250:

Billable revenue = ($150 × 25) + ($100 × 15) = $5,250

To keep time entry consistent, most professional services firms track billable hours in fixed increments, rather than by the minute. The most common increment is six minutes, or one-tenth of an hour (0.1), so shorter activities can be tracked without resorting to rough estimates and billed accordingly. Larger increments—15 minutes (0.25 hour) or 30 minutes (0.5 hour), for example—can simplify tracking but tend to introduce more rounding, which can lead to disputes.

How Are Billable Hours Recorded?

Accurate recording of billable hours involves more than just tracking time. Professional services firms rely on a methodical system and repeatable habits that capture work consistently. The following five steps compose a detailed process that supports the workflows of marketing agencies and other professional services providers:

  1. Set the hourly rate: Firms should define clear billing rates for each role and service type they’re providing before they start recording any time. Billing rates may differ based on level of experience—senior strategists, for instance, usually command a higher hourly rate than junior coordinators; ideally, the pay rates will be documented in the contract or engagement letter. Diligently recording this information helps both the firm and its clients understand how hourly charges will be handled during the project.
  2. Set a payment schedule: Firms and clients should determine whether invoices will be issued weekly, biweekly, monthly, or at specific milestones, and set payment terms, such as within net 15 or net 30 days, to give clients enough time to review and approve invoices without causing payment delays. Consistent payment schedules also support cash flow management and minimize administrative costs associated with addressing or resolving client invoice disputes.
  3. Carefully track project hours: To minimize forgotten or misclassified work, team members should record time spent on each client and project at or shortly after task completion. Although this can be done manually with spreadsheets, many firms now employ time tracking software that integrates the task into their broader systems, allowing employees to tag entries with client or project identifiers and sync the data to prevent duplicated records.
  4. Total the billable hours: At the end of each billing period, recorded time is aggregated by client and project and reviewed for accuracy. This quality control step helps disclose missing or duplicate logs, determines whether all listed tasks are actually billable, and checks that all hours are associated with the right client. Write-downs, billing caps, and any other agreed-upon exceptions are also accounted for in this step so only approved billable hours will be invoiced.
  5. Generate the client invoice: Once approved hours have been tallied, they should be multiplied by the agreed-upon rates to determine the invoice charges. The use of itemized invoices can help avoid confusion and demonstrate the value delivered with more transparency. Invoices should include information regarding the work performed, the hourly rate for every individual role or service, and the time dedicated to each task. Many businesses rely on automation tools to create invoices directly from client-accepted project entries, cutting back on human effort and errors and shortening the path from completed work to cash collected.

Billable Hours and Utilization Rates

Utilization rate is a metric used to track employee billable productivity; it compares the total hours a team member worked for the company to the billable hours they logged on clients and projects. Utilization rates are among the most important metrics for professional services companies, because they reflect how efficiently hours worked are converted into revenue.

The formula is straightforward:

Utilization rate = (Billable hours / Total available hours) × 100

For example, if an employee works 40 hours a week and logs 30 billable hours, their utilization rate is 75%—(30 / 40) x 100 = 75%. If available hours are calculated annually (say, 1,900 hours after accounting for PTO and holidays), a 75% utilization rate would translate to roughly 1,425 billable hours per year.

Utilization rates can also be used to spot workflow patterns that help leaders identify possible uneven workloads or the reasons behind project delays. Industry research shows that billable utilization across professional services firms averaged 68.9% in 2024, according to SPI Research’s “2025 Professional Services Maturity Benchmark”—below what many consider the 75% optimal threshold. The goal is to maintain a balanced utilization rate: Consistent 85% to 90% rates will most likely result in burnout and lower-quality output, while an underutilized staff could indicate poor project flow or excessive time spent on internal work.

Challenges in Tracking Billable Hours

Tracking billable work accurately can be harder than it appears. In the context of marketing agency and professional services work, tasks and projects often overlap and client requests constantly disrupt planned schedules. Leaving time-logging for “when things calm down” in favor of completing immediate client work may seem like a good way to generate revenue, but it risks incomplete or inaccurate records. Here are some common challenges teams face when tracking billable hours for different projects:

  • Inaccurate time tracking: When employees rely on memory when logging their work at the end of the day—or week—important details can easily be missed, small tasks tend to be forgotten, and work can be logged under the wrong project. Over time, inaccurate or incomplete records can result in underbilling, which affects revenue, or erroneous charges, which undermines client confidence.
  • Administrative burden: Recording, reviewing, and approving time entries for invoicing takes time. Generating those invoices also consumes availability that could otherwise serve to generate revenue with clients. When manual timesheets or fragmented systems that require team members to enter information into multiple tools are used, the added workload can discourage timely entry—and the risk of errors increases.
  • Untracked billable time: If a firm doesn’t use small enough time tracking increments, brief requests, client check-ins, or unscheduled tasks may feel too minor to log. As quick or simple as these tasks may seem, this pattern can leave time unaccounted for and revenue on the table.
  • Tracking across different client requirements and billing structures: Professional services companies are known for offering diversified billing options; some clients prefer hourly invoicing, others opt for project-based payments, and some prefer the continued support of retainer agreements. Each structure has its own tracking and invoicing requirements, and keeping them in order demands clear processes and flexible systems.

How NetSuite Helps Accurately Track Billable Hours

NetSuite cloud accounting software integrates time tracking with finance and project management, giving teams real-time visibility into billable hours and corresponding revenue. Employees log time against specific projects as work is completed, and automated workflows move approved hours directly into itemized invoices—reducing the potential for delays, duplicate entries, and client pushback. Integrated reporting lets managers monitor utilization rates, compare planned versus logged time, and spot projects at risk of running over budget, thereby providing a foundation for accurate billing and smarter resource decisions.

Billable hours are the foundation of how marketing agencies and most professional services firms record employee time and generate revenue. When tracking is done in an accurate and meaningful way, billable hours become a reliable financial input that supports defensible invoicing, profitability management, forecasting, and resource and capacity planning. Postponed logging of time entries and administrative overhead could interfere with billable hours management, but firms that want to capture more of the value they create can rely on a mix of tools and processes to ease that friction. As client demands evolve and billing models diversify, companies that view and manage billable hours as structured data will be better positioned to plan ahead and adapt without losing financial clarity.

Billable Hours FAQs

Which professions commonly use billable hours?

Billable hours are commonly used in marketing and advertising, law, consulting, accounting, architecture, engineering, and IT services. Any profession that provides client-specific services on an ongoing or project basis tends to rely on hourly billing.

How are billable hours tracked?

Time tracking platforms are often used to record billable hours. Some tools have built-in, real-time tracking options, while others rely on manual entry at the end of each day.

What are examples of billable hours?

Billable hours include any time spent directly on client work, such as strategy sessions, creation of deliverables, client meetings, research for a specific project, client calls and emails, and—depending on the contract—travel to client sites.

What are examples of non-billable hours?

Non-billable hours are usually the internal activities that don’t directly advance a client project. Team meetings, training, business development, proposal writing, administrative tasks, and general operations are not usually considered to be billable hours. Though essential to running the business, these hours can’t be charged directly to a single client.