Bookkeeping for Plumbing Contractors

Plumbing contractor bookkeeping demands more than transaction categorization and bank reconciliation. Your business runs on job costing across wildly different service types, managing a rotating cast of subcontractors, tracking parts inventory across multiple trucks, and calculating labor burden rates that vary dramatically by skill level. A generic bookkeeper will miss all of this.

Steph's Books provides outsourced bookkeeping for plumbing contractors across the country. We configure your books to track profitability by service type, manage subcontractor payments and 1099 compliance, and deliver monthly financial statements that actually tell you how your business is performing. We are also a preferred bookkeeping vendor for ServiceMaster franchise owners.

Why Plumbing Bookkeeping Is Different

Revenue Mix Determines Everything

Not all plumbing revenue is created equal. The profitability gap between service types is enormous:

• Drain cleaning — 50–70% gross margin
• Service and repair — 40–55% gross margin
• Remodels / retrofits — 25–40% gross margin
• New construction — 10–18% gross margin

A company doing 70% service/repair work is worth 2.5–4x seller's discretionary earnings at sale. A company heavily weighted toward new construction drops to 1.5–3x. If your books do not separate these revenue streams, you cannot see the blended margin distortion — and you are almost certainly underpricing some work while overpricing other work.

Job Costing Across Service Types

A 15-minute drain snake and a 6-week new construction rough-in have nothing in common financially. Yet most plumbing companies track both under a single "Revenue" and "Cost of Goods Sold" account. We set up your QuickBooks with service-type classes and per-job cost tracking so you can answer the question every plumbing owner needs answered: *which jobs actually made money?*

Subcontractor 1099 Management

Plumbing companies routinely subcontract overflow work and specialized tasks — gas line work, drain camera inspections, trenching, backflow testing. Each sub needs a W-9 on file before the first payment, and any sub paid $600 or more in a calendar year requires a 1099-NEC filing.

The IRS penalty for a missing 1099 is $310 per form. For a plumbing company with 15 active subs, that is $4,650 in potential fines — from paperwork alone. We track every subcontractor payment throughout the year so year-end filing is routine, not an emergency.

Truck Stock and Parts Inventory

Every service truck is a mobile inventory hub. Technicians pull parts from the truck on jobs but often do not log what they used. This "shrinkage" — lost, stolen, or untracked parts — directly erodes job profitability. If a $350 service call used $80 in parts that were never recorded, your actual margin is 23% lower than your books show.

We help you implement truck stock reconciliation workflows so your cost of goods sold reflects reality, not estimates.

Tiered Labor Costs

Plumbing labor costs vary dramatically by skill level:

• Apprentice — $20–$45/hr base, $27–$60/hr fully loaded
• Journeyman — $27–$90/hr base, $36–$120/hr fully loaded
• Master Plumber — $75–$130/hr base, $100–$175/hr fully loaded

The "fully loaded" cost includes payroll taxes (7.65% FICA), workers' comp (approximately $2.65 per $100 of payroll for plumbing), health insurance, tool allowances, and vehicle costs. If you are not calculating burden rates per labor tier, you are underpricing every job staffed with senior plumbers and overpricing apprentice work.

Warranty Reserve Accounting

Industry best practice is to set aside 1–2% of job revenue in a warranty reserve account. This is recorded as an "Other Current Liability" on the balance sheet — not expensed immediately. When warranty callbacks happen, the cost draws from the reserve rather than hitting your P&L as a surprise expense. Most plumbing contractors do not track this, leading to unpredictable profit swings.

Plumbing Industry Financial Benchmarks

• Gross profit margin (target) — 60–62%
• Net profit margin (well-run) — 10–20%
• Net profit margin (poorly managed) — 2–3%
• Median plumber wage — $62,970/year (BLS, May 2024)
• Revenue per plumber — $338K–$380K
• Workers' comp rate — ~$2.65 per $100 payroll
• Billable hour efficiency — 30% avg, 50% excellent
• Typical overhead — 30–45% of revenue