How to buy a plumbing business (and check the numbers first)
Short answer
To buy a plumbing business, first find out which business it really is: residential service and repair (call-driven, higher margins), drain and sewer work, or new construction (contract-driven, thinner margins, builder concentration). Then verify call volume, average ticket and technician productivity from the dispatch software, check who holds the master plumber or contractor licence, and look at callbacks, fleet condition and lead sources.
Plumbing businesses are steady because pipes break in every economy. Value depends on whose phone rings and who's licensed to answer it.
Three businesses under one name
Residential service
Emergency and repair calls, water heaters, fixtures. Many customers, higher margins. Watch average ticket and close rate.
Drain and sewer
Camera inspections, jetting, line replacement. Equipment-heavy, high tickets. Check equipment age and permits.
New construction
Rough-in and finish for builders. Volume tied to a few GCs and the housing cycle; retainage and slow pay.
Metrics to rebuild from the data
| Metric | Source | Why |
|---|---|---|
| Calls per month, by type | Dispatch software | Demand trend |
| Average ticket | Invoices | Pricing power |
| Revenue per technician | Jobs by tech | Productivity; owner's share of work |
| Repeat customer rate | Customer IDs | Loyalty to the business vs the owner |
| Callbacks | Job notes, no-charge invoices | Quality and hidden costs |
| Builder concentration | Revenue by customer | New construction risk |
Worked example: revenue per technician and the owner on the truck
Illustrative example, not a real company or market rates
A residential service company runs 5 trucks. Dispatch data shows 4,600 jobs last year at an average ticket of $520, so $2,392,000 of service revenue. By technician: the owner ran 1,150 jobs averaging $680 ($782,000), four techs ran 3,450 jobs averaging $467 ($1,610,000). The owner's ticket is higher because he sells water heaters and repipes on his calls. If he steps off the truck after closing and a new tech closes like the others, those 1,150 jobs bring about 1,150 × $467 = $537,000, a $245,000 drop in revenue. At a 50% gross margin on that work in this example, that's $122,500 less gross profit, on top of the new tech's wages. Owner production is often the hidden half of the owner salary add-back in trades businesses.
Licences and add-back traps
- Plumbing contractor licensing is state and often locally regulated; many require a licensed master plumber responsible for the business. Plan this before the LOI. See transferring licenses.
- Owner's labor: if the seller runs a truck, SDE includes a full technician's output.
- Vehicle add-backs for work vans.
- "One-time" callbacks that happen monthly.
Documents to request
- Dispatch/field software exports; invoices; tax returns; bank and processor statements.
- Licences and responsible licence holders; insurance; claims.
- Fleet, equipment (cameras, jetters) and inventory lists.
- Builder contracts and receivables aging if new construction.
- Technician roster, pay, tenure, certifications.
Licences, permits and safety
Most states license plumbers individually (apprentice, journeyman, master) and many license plumbing contractors through a qualifying master plumber. Permits for water heaters, repipes and sewer work are pulled under that licence. If the seller is the master plumber, you need a licensed replacement in place before closing, and you should check whose licence number appears on recent permits. Sewer line and excavation work brings OSHA's excavation and trenching rules, which are frequently cited and dangerous to ignore; ask about the safety program and any incidents. Backflow testing, gas line work and medical gas often need separate certifications.
Worked example: new construction vs service margins
Illustrative example, not a real company
A company does $3.0 million: $1.8 million residential service and $1.2 million new-construction rough-in and finish for two builders. Service gross margin is 52% ($936,000); new construction is 24% ($288,000). New construction is 40% of revenue but under a quarter of gross profit ($288,000 ÷ $1,224,000), it ties up crews for weeks at a time, and the builders pay in 60 to 90 days with retainage. If housing starts slow and the builders cut back, the company loses revenue that matters less than it looks, but it also keeps crews it may not need. Ask for gross margin by type of work, builder receivables and retainage, and how crews would be redeployed if builder work fell.
What moves the value of a plumbing company
We don't value deals or publish multiples we can't verify. Appraisers and lenders weigh these factors:
| Factor | Supports a higher value | Pulls it lower |
|---|---|---|
| Mix | Residential service with repeat customers | Mostly new construction for a few builders |
| Licence | Master plumber who stays | Seller is the only master |
| Owner role | Office runs dispatch; techs sell | Owner runs calls and sells big jobs |
| Lead sources | Repeat, referral, maintenance plans | One paid channel |
| Fleet and equipment | Maintained trucks, cameras, jetters | Old fleet, deferred replacement |
Red flags specific to plumbing companies
- Permits pulled under someone else's licence, or work done without permits.
- Builder receivables that are old or disputed, with retainage unpaid.
- One builder supplying most of the new-construction work.
- Sewer and excavation work without a trenching safety program.
- Water heater installs billed at flat prices that no longer cover parts costs.
- A dispatcher or office manager who runs everything and has no plans to stay.
The first 90 days after you buy
Make sure the licence, insurance and permits work for your entity on day one, and that the phone number, website and online listings come with the business: in residential service, the phone ringing is the business. Keep technicians on the same pay and trucks, ride along on calls, and watch call volume, average ticket and callbacks weekly. If the seller sold the large jobs, have him train whoever will take that role before he leaves.
Maintenance agreements and memberships
Many plumbing companies sell annual maintenance plans or memberships: an inspection, priority service and a discount. These give steady revenue and repeat visits, but they come with obligations. Ask for the number of active members, renewal rates, what each plan promises and how much of the year's service is still owed. Prepaid plans are revenue collected for work you will do, so ask for a credit at closing for the unserved portion.
Warranty and callback history
Ask for callbacks and warranty jobs for the last two years: how many, what for and what they cost. Water heater and fixture installs often carry both a manufacturer warranty and the company's own labor warranty. Agree in the purchase agreement who handles and pays for warranty work on jobs finished before closing.
Questions to ask the seller
- What are jobs, average ticket and revenue by technician, including you?
- Whose licence are permits pulled under, and will that person stay?
- What share of revenue comes from builders, and on what payment terms?
- What did callbacks and warranty work cost last year?
- Which lead sources produce the most calls, and what do they cost?
- How old are the trucks and major equipment?
Before closing, ride along with a service technician for a day. Watch how calls are priced, whether the technician presents options, and how invoices are collected on site. These habits drive revenue per call more than the marketing does.
Check how the company handles permits on the jobs it does. Ask for the permit history for the last year, and compare it with the job list for work that normally needs one. Unpermitted work can lead to fines, failed inspections at resale of a customer's home, and claims that come back to the company long after the job was paid.
Frequently asked questions
Do I need to be a licensed plumber to buy a plumbing business?
Not always, but the business usually needs a licensed master plumber or qualifier under state or local rules. If that's the seller, you need a licensed person in place before closing.
Is residential service better than new construction?
Service usually has higher margins and more customers; new construction depends on a few builders and the housing cycle. Many businesses do both; value them separately.
How do I check plumbing revenue?
Dispatch and invoicing data by job, matched to card processor statements and bank deposits; customer counts and repeat rates.
What hidden costs are common?
Callbacks and warranty repairs, vehicle replacement, tool and inventory losses, and technician turnover.
How do I verify a plumbing company's revenue?
Tie jobs and invoices in the dispatch or field service software to the P&L, card processor statements and bank deposits. For new construction, check contracts, pay applications and retainage. Parts and water heater purchases from supply houses are a useful cross-check on service volume.
What metrics matter most in a plumbing service company?
Calls booked per week, close rate on estimates, average ticket, revenue per technician per day, callbacks, and the share of work from repeat customers or maintenance plans. Get them from the dispatch or field service software for 24 months, by technician.
Sources
- SBA SOP 50 10 8.1, Appendix 15
- OSHA Construction standards, 29 CFR Part 1926 (including excavation and trenching)
- IRS: Independent contractor or employee?
- IRS Publication 946 (vehicles and equipment)
Related guides
General information, not legal, tax, financial or investment advice. Rules and lender practices change; check the linked sources and talk to your attorney, CPA and lender about your deal. Examples with named numbers are illustrations, not real businesses. OKtoBuy's Deal Check does not value businesses or give price opinions.