General and administrative expenses for professional service firms: What counts, what it costs, and why your billing rate depends on it

A 12-person management consulting firm runs a profitability review. Revenue looks healthy. Margin looks acceptable. Then someone maps which costs are G&A and which are direct costs, and discovers that $180,000 categorized as overhead is actually shared practitioner time and project-specific software subscriptions. The corrected G&A ratio drops from 31% to 19%. The billing rate they calculated was 18% too high. They had been losing bids they should have won for two years. Not because their costs were high, but because they did not know which costs were which.

This is not a rare situation. It is the standard one for professional service firms that have been tracking expenses without separating the overhead layer from the delivery layer.

What counts as G&A and what does not

The G&A boundary matters more in a service firm than in almost any other type of business. Unlike a manufacturer with a clear production floor, a professional service firm has costs that sit in a grey zone between delivery and administration. Getting the boundary wrong produces billing rates that are either too high, making the firm look expensive against competitors, or too low, making the firm unprofitable on every engagement.

Clearly G&A: management and leadership salaries and benefits (partners who are not billing to clients, operations directors, HR managers), rent and facilities costs not specific to client work, back-office software (accounting systems, HR platforms, general IT infrastructure), professional fees for external accountants and lawyers, office administration staff, and general insurance and compliance costs that apply to the whole firm.

Clearly not G&A: practitioner salaries and benefits, subcontractor fees for client engagements, project-specific software and tools billed to or used for specific clients, client-facing travel and accommodation, and direct training tied to specific engagement skills.

The grey zone: software subscriptions used for both delivery and administration (a project management tool used by practitioners and the admin team alike, for example) should be allocated by actual usage ratio. Semi-dedicated administrative staff whose time splits between internal and client-facing coordination should be split by function. Office space in locations that serve both client hosting and internal operations is typically classified as G&A.

The reason the distinction matters is not accounting tidiness. It is that G&A and billable vs non-billable expenses serve different financial purposes. G&A must be recovered through client billing by being built into the billing rate. Direct costs are tracked per engagement to measure engagement profitability. Mixing them makes both calculations unreliable.

G&A expenses vs cost of services: The boundary by category

G&A vs cost of services: The income statement difference

Service firms do not have cost of goods sold in the traditional sense. They have cost of services (COS): the direct costs of delivering client work. The income statement for a professional service firm has two distinct cost layers, and both must be visible for the numbers to be useful.

Layer 1: Cost of services. Practitioner salaries, subcontractor fees, direct project expenses. Subtracted from revenue to produce gross margin. A well-run professional service firm typically targets gross margin between 35% and 60%, depending on the type of work and billing model.

Layer 2: G&A. Overhead and administrative costs not tied to delivery. Subtracted from gross margin to produce operating profit. This is the layer that most professional service firms either conflate with cost of services or treat as a single undifferentiated overhead line.

When COS and G&A are combined into a single overhead category, the income statement cannot show gross margin. Without gross margin, the firm cannot measure delivery efficiency, cannot benchmark against industry peers, and cannot see whether a specific service line is profitable before overhead allocation. Every decision about pricing, hiring, and service mix is being made from an incomplete P&L.

G&A ratio benchmarks for professional service firms

The G&A ratio is calculated as G&A expenses divided by net revenue, expressed as a percentage. It is the most direct measure of how efficiently a firm manages its overhead layer.

The ratio changes predictably with firm size. Firms with 5 to 10 staff typically run a G&A ratio of 8 to 15% because founders are billing directly and there is minimal administrative overhead. Between 10 and 25 staff, the ratio typically climbs to 15 to 25% as management layers form for the first time and the firm hires its first operations or finance person. A principal stops billing full time to focus on sales and business development. G&A can climb from 15% to 28% in 12 months without the firm noticing because revenue is also growing and masking the shift.

G&A above 30% at any size warrants investigation. Above 35% typically signals that management overhead has grown faster than billable capacity, often during a period of rapid hiring where administrative costs were added without corresponding revenue growth.

The consulting profit margin leaks that most commonly surface when a firm first properly tracks G&A are management time that was never formalized as overhead, software subscriptions accumulated piecemeal across teams, and administrative staff whose scope expanded gradually without review.

G&A ratio benchmarks by firm type and size

How G&A feeds into billing rate construction

Most professional service firms set billing rates by instinct or market comparison. The firms that undercharge consistently are almost always the ones that do not know their G&A ratio. They have built a rate on partial cost information and are subsidizing client work from margin that does not exist.

The billing rate formula

Billing rate = (fully loaded practitioner annual cost + overhead allocation + G&A allocation + target profit margin) ÷ annual billable hours target

For a practitioner with a fully loaded annual cost of $120,000, at a firm with 1,600 target billable hours, a 20% overhead rate, and a G&A ratio of 18%:

• Fully loaded practitioner cost: $120,000
• Overhead allocation: $24,000 (20% of $120,000)
• G&A allocation: $21,600 (18% of fully loaded cost)
• Total cost to firm: $165,600
• Add 30% profit margin: $215,280
• Divide by 1,600 billable hours: $134.55 minimum billing rate

When G&A is miscategorized and appears lower than it actually is, the allocation is understated. The billing rate comes out at $118 instead of $134. The firm wins more bids. The firm also loses money on every engagement.

G&A is a real cost of running the firm that must be recovered through client billing. If a firm carries $200,000 in annual G&A and bills 8,000 practitioner hours per year, each hour must recover $25 in G&A contribution just to break even on overhead. A firm that does not include G&A in its billing rate calculation is subsidizing client work from profit it does not have.

Tracking G&A monthly and reducing it without cutting capacity

Three G&A categories that grow silently in most professional service firms

Management time that was never accounted for. As a firm grows, founding partners spend less time billing and more time managing. That shift from 80% utilization to 50% utilization represents a real G&A cost that many firms never formalize. The principal's salary remains the same. The G&A impact of their reduced billing doubles, because the same cost is now producing half the billable output.

Software subscriptions. A well-intentioned operations team can accumulate $3,000 to $8,000 per month in SaaS subscriptions without a single deliberate decision. Each tool seemed reasonable when added. The cumulative G&A impact is rarely reviewed against revenue. A quarterly software audit of the G&A line alone typically recovers $500 to $2,000 per month in most firms between 10 and 30 staff.

Administrative staff scope creep. An office coordinator hired at $55,000 to handle scheduling and supplies has, two years later, become a $72,000 operations manager running onboarding, vendor relationships, and firm-wide events. The scope growth may be entirely justified. The G&A impact has not been reviewed against the revenue growth it enabled.

Monthly G&A tracking does not require a complex system. The G&A line-by-line review should compare current month G&A to the prior three months and to the percentage of revenue. A consistent upward trend in G&A ratio, even while revenue grows, is an early warning that overhead is not being managed proportionally. Pair this with the chart of accounts for consulting already set up for service line segmentation, and the G&A review becomes a 20-minute monthly process rather than a quarterly scramble.

The firms that have a G&A problem almost never know it until the billing rate pressure becomes obvious. By then, the rate card has been wrong for 18 months and the client relationships built on that rate are difficult to reprice. Cleaning up G&A categorization, calculating the real ratio, and embedding G&A into rate construction is the work that happens before a pricing conversation, not after it.

Frequently asked questions

What is the difference between G&A expenses and overhead?

Overhead broadly covers all indirect business costs that are not tied to a specific deliverable. G&A is a specific subset: the costs of administering and running the firm itself, separate from both direct delivery costs and selling expenses. In practice, most professional service firms use the terms interchangeably, which creates reporting confusion, particularly when comparing G&A ratios against industry benchmarks or preparing financial statements for investors or lenders.

Are G&A expenses tax deductible?

Yes. Ordinary and necessary G&A expenses are generally deductible as business expenses under IRC Section 162. This includes management compensation, rent, professional fees, insurance, and back-office software. The IRS distinguishes between currently deductible expenses and capital expenditures that must be depreciated over time. The IRS Guide to Business Expense Resources provides the current reference for each expense type. A tax professional should review any G&A expenses that could be characterized as capital improvements or multi-year assets.

How do you allocate G&A expenses across service lines?

The two standard methods are revenue-based allocation (each service line bears G&A in proportion to its share of total firm revenue) and headcount-based allocation (G&A is split by the number of practitioners in each service line). Revenue-based allocation is simpler and more commonly used. Headcount allocation is more accurate when service lines have significantly different revenue per practitioner. Some firms allocate identifiable G&A directly to the service line that caused it, then spread the remainder by revenue share.