Reading a P&L Statement for a Service Business
Why this matters
Most small field-service operators can't read their own P&L. The CPA hands it over at year-end + the owner stares at it for 90 seconds + files it away. That gap is the #1 reason contractors run out of cash in year 3. The P&L isn't accounting trivia - it's the operating dashboard that tells you whether the business actually makes money, where the leaks are, + what to fix next.
The five sections of every P&L
A Profit & Loss statement (also called Income Statement) breaks into:
- Revenue (top line)
- Cost of Goods Sold (COGS) - direct cost of delivering the service
- Gross Profit = Revenue − COGS
- Operating Expenses - everything else to run the business
- Net Profit = Gross Profit − Operating Expenses
These five numbers tell the whole story. Everything else is sub-detail.
Revenue (top line)
What you billed customers in the period. Cash basis = when paid; accrual basis = when invoiced. Service businesses usually run accrual for the accurate picture, cash for tax purposes.
Break revenue into service-line buckets:
- Recurring maintenance (highest-margin)
- Repairs (mid-margin)
- Installs / replacements (volume-driver)
- Emergency / after-hours (premium)
- Membership / club dues (recurring)
The mix matters more than the total. A M service business that's 80% installs + 20% maintenance has different economics than one that's 40% recurring + 60% repairs.
Cost of Goods Sold (COGS) - the trade-specific line
In a service business, COGS includes everything directly tied to delivering the job:
- Direct labor: technician wages + payroll taxes + workers comp on hours billed to jobs (NOT office staff)
- Materials: parts, supplies, sub-contracted work
- Vehicle costs allocated to jobs: fuel + maintenance (some operators put these in OpEx; the IRS allows either; pick one + stay consistent)
- Subcontractor payments: when you hire out portions of work
- Job-specific permits + fees
What's NOT in COGS:
- Office staff wages
- Owner's salary (typically OpEx)
- Marketing
- Office rent
- General insurance
- Software + tech subscriptions
Gross Profit + Gross Margin
Gross Profit = Revenue − COGS
Gross Margin % = Gross Profit ÷ Revenue × 100
Healthy gross margin by trade:
- HVAC residential: 35 - 50%
- Plumbing residential: 35 - 50%
- Electrical residential: 35 - 50%
- Roofing residential: 25 - 40%
- Cleaning residential: 40 - 60%
- Pool service: 40 - 60%
- Pest control: 50 - 70%
- Lawn care: 35 - 55%
- Tree service: 25 - 40%
Below the trade benchmark = you're either underpricing OR overspending on direct labor + materials.
Operating Expenses (OpEx) - the rest
Everything to run the business that isn't a direct job cost:
- Office salaries + owner pay: dispatcher, CSR, bookkeeper, owner
- Marketing: ads, lead gen, referral payouts
- Office rent: shop, warehouse, office
- Insurance (non-WC): GL, vehicle, umbrella, EPLI
- Vehicle leases / payments: if not allocated to COGS
- Office vehicle fuel + maintenance: non-billable miles
- Software subscriptions: CRM, QuickBooks, dispatch
- Phone + internet
- Office supplies
- Continuing education + training
- Professional services: accounting, legal, consulting
- Depreciation: vehicles, equipment, computers
- Interest on loans
Net Profit + Net Margin
Net Profit = Gross Profit − Operating Expenses
Net Margin % = Net Profit ÷ Revenue × 100
Healthy net margin for residential service business: 8 - 18% pre-tax.
Below 8%: structural problem; review pricing + labor cost + overhead. Above 18%: either an exceptional operator OR pricing premium OR underinvesting in growth.
The number most owners get wrong: their own pay
The "owner's salary" question:
- If owner works in the field: their billable hours' labor cost belongs in COGS (just like any tech)
- If owner runs the business: their salary belongs in OpEx
- If owner does both: split it; reasonable allocation based on time
Pretax net profit AFTER paying yourself a market salary is the real number. Owners who don't pay themselves + show 20% "profit" are kidding themselves - that profit IS their compensation + the business isn't earning what they think.
Reading the P&L month-over-month
Monthly comparison reveals trends:
- Revenue declining 3+ months: marketing OR sales OR seasonality issue
- COGS % rising 2+ months: material costs up OR labor over-allocated OR pricing eroded
- OpEx growing faster than revenue: scope creep OR poor cost discipline
- Net margin declining: one of the above
The pattern matters more than any single month.
Comparing to industry benchmarks
Industry surveys (PHCC for plumbing/heating, IEC for electrical, ASEC for HVAC, etc.) publish annual cost-of-doing-business data. Compare your P&L line items to industry medians:
- Direct labor as % of revenue
- Materials as % of revenue
- Marketing as % of revenue
- Total OpEx as % of revenue
This calibration tells you where you're above or below peers. Numbers way above peers = leak. Numbers way below = either lean operation OR underspending (e.g., 0% marketing = stalled growth).
The single highest-value habit for a service-business owner is the MONTHLY P&L REVIEW - 30 minutes on the 5th - 10th of the following month, with your bookkeeper. Read every line. Compare to last month + same month last year. Flag what changed. Most owners avoid this because they don't understand the document; the act of doing it every month + asking the bookkeeper "what is this" teaches you the document. After 6 months, you'll read it fluently + catch issues before they sink the business.
Cash vs accrual (the basics)
- Cash basis: revenue when paid; expenses when paid
- Accrual basis: revenue when earned (invoiced); expenses when incurred (billed)
Most service businesses operate on accrual for management + cash for tax. Your bookkeeper or accountant chooses; you should know which.
Accrual reveals lag between work + payment - important for collections + cash flow. Cash hides this.
What a P&L DOESN'T tell you
The P&L is profit. The cash flow statement is cash. They're different:
- A profitable business can run out of cash (if customers don't pay fast enough)
- A money-losing business can have cash on hand (financed loss, prepaid revenue)
Owner needs to read BOTH. P&L tells you if you're earning; cash flow tells you if you can pay the rent next week.
References
- "Profit First" by Mike Michalowicz (service business application)
- IRS Publication 535 (Business Expenses)
- PHCC, NECA, ACCA cost-of-doing-business surveys
- QuickBooks + Xero help documentation
- Manuall internal: Financial KPIs for a Service Business, Weekly Cash Flow Forecast SOP