How to Grow a Plumbing Business
A plumbing business that grows on callouts alone just gets busier. Here's how to build recurring compliance work, choose the right clients, and add a second van without losing money on it.
There's a version of a plumbing business that's flat out and going nowhere: the phone rings, you go, you fix it, you go home and quote until midnight. It feels like a growing business and it's actually a job with worse hours. Real growth in plumbing comes from work that recurs on a date rather than an emergency, clients who pay what the work is worth, and adding people at the point where a second van pays for itself. Here's how to get there. That's a capacity problem rather than a lead problem — if the phone isn't ringing enough in the first place, start with how to get more plumbing leads for where the work comes from, and marketing a plumbing business for how you're positioned.
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Work out which jobs are carrying the business
Plumbing generates a lot of small jobs, and small jobs hide their true cost. The drive, the wholesaler stop, the ten minutes writing it up — none of that is on the invoice, and all of it is on your day.
- Margin by job type. Blockages, hot water, tapware, bathroom rough-ins, maintenance callouts. Compare quoted to actual on each, not revenue.
- Cost per callout. Total travel, diagnosis and admin time divided by the number of jobs. If that number is close to your minimum charge, your minimum charge is too low.
- Client profitability. An agency sending you steady work at low rates on 45-day terms may be worth less than fewer, better-paid direct jobs.
- Return visits. Warranty callbacks and jobs that needed a second trip for a part you didn't have. Both are fixable and both are pure loss.
Two months of honest job costing will change what work you chase. It usually shows the same thing: the emergency work everyone assumes is the money-maker is fine, but the small maintenance jobs are being run at or below cost because the minimum charge was set years ago and never revisited.
Build the recurring compliance base
Plumbing has some of the best recurring revenue available to any trade, because several types of work carry a legal testing interval. The customer must have it done, on a date, every year — and whoever did it last year is who they ring.
- Backflow prevention device testing — annual, mandatory for the devices it applies to, and one of the strongest recurring revenue lines in the trade. It needs an endorsement, and getting it is worth the effort.
- Thermostatic mixing valve servicing — required at set intervals in healthcare, aged care, childcare and similar facilities. Scheduled, repeatable and paired with a client who has many of them.
- Commercial and strata maintenance agreements — periodic inspections of a building's plumbing, sold as a plan rather than a callout.
- Hot water system servicing — every unit you install is a service and eventually a replacement. Track them by address and diarise it.
- Grease trap and drainage servicing for hospitality clients — regular, unglamorous, reliably paid.
Recurring compliance work is worth more than its revenue. It gives you a booked forward diary, which is what tells you whether you can afford a second plumber — and it turns the quiet weeks between emergencies into scheduled days.
Choose your clients deliberately
Most plumbing businesses accumulate clients rather than choosing them, and then wonder why the margin is thin. Each client type comes with a rate, a payment term and a level of hassle attached. Know what you're signing up for.
| Client | What you get | What it costs you |
|---|---|---|
| Direct homeowners | Best rates, fastest payment, referrals | You have to market for them |
| Real estate agencies | Steady volume, fills quiet weeks | Lower rates, longer terms, tenant coordination |
| Strata managers | Repeat work across many properties | Approval processes and slower decisions |
| Builders | Large predictable volume | Their payment cycle and their programme |
| Insurance work | Reliable flow after events | Assessor paperwork, scope disputes, set rates |
| Commercial and facilities | Contracts and recurring maintenance | Response-time obligations and compliance paperwork |
A healthy mix usually has a base of recurring commercial or agency work that covers fixed costs, and direct residential work that provides the margin. What you don't want is a business that's entirely one column — all agency work means thin margins, and all direct work means no floor under a bad month.
Adding the second van
The second van is the hardest step in a plumbing business. It roughly doubles your fixed costs overnight, and it only pays off if there's enough work booked to keep it moving — not enough work that you hope will turn up.
- The test is forward bookings, not busyness. If you've got weeks of scheduled work you're pushing back, you're ready. If you're just flat out reacting, hiring will make the chaos bigger.
- Fit out the van before the plumber starts. A second plumber without stock spends their week at the wholesaler on your dime.
- Know the full cost. Wage, superannuation, workers compensation, leave, vehicle, fuel, tools, stock, insurance and phone. Requirements and rates vary by state — check with your state authority and your accountant.
- A subbie is the lower-risk trial. Use one to test whether the work volume is real before you take on an employee.
- An apprentice is a long play. They add supervision load before capacity, and the return arrives in later years.
- Consider admin first. If you're doing fifteen hours of quoting and invoicing a week at night, buying those hours back is often cheaper and faster than a second plumber.
Our guide to what your first employee costs works through everything that sits on top of the wage.
Fix the admin so growth doesn't break it
Plumbing admin scales badly. Twenty jobs a week is manageable in your head; fifty isn't, and the failures show up as unquoted variations, uninvoiced jobs and customers you never followed up. Sort the system before the volume arrives.
- Capture every enquiry. Missed calls are the biggest leak in a plumbing business. Every call, text and web form needs to land somewhere that survives your memory.
- Quote and invoice on site. Small maintenance work should be invoiced before you drive away. It's faster, the customer's memory is fresh, and payment terms start immediately.
- Schedule the crew from one place. Once there's more than one van, everyone needs the same job details — address, access, what's wrong, what was quoted — on their phone.
- Diarise every recurring service. Backflow tests, TMV services, hot water servicing. Booked twelve months ahead, they're the base your growth stands on.
- Chase overdue invoices automatically. Not when you remember. A reminder the day after due date is normal business and it dramatically shortens how long you wait.
ServiceYak keeps enquiries, quotes, jobs and invoices on the one system — rates in a reusable kit for quoting on site, jobs pushed to the crew's phones with the details attached, and reports showing estimated against actual cost on every job you close.
Frequently asked questions
How do I grow a plumbing business beyond just being busier?
Build recurring compliance work that arrives on a date rather than an emergency — backflow testing, TMV servicing, maintenance agreements — and use it as a booked forward diary. Then measure margin by job type and client, and rebalance toward the work that actually pays. Volume alone just makes the same margin problem larger.
When should I put on a second plumber?
When you have weeks of scheduled work you're pushing back, not just when you feel flat out. A second van roughly doubles your fixed costs the day it starts, so it needs booked work to cover it. Trialling with a subbie first is the low-risk way to test whether the volume is real.
Is real estate and strata work worth taking?
As a base, yes. It's steady, it fills quiet weeks and it's low-effort to win. But the rates are lower and the terms are longer, so it works as the floor under your business rather than the whole of it. Pair it with direct residential work that carries the margin.
What's the best recurring revenue for a plumbing business?
Compliance testing with a mandated interval — backflow prevention device testing and thermostatic mixing valve servicing are the standouts, because the customer has a legal obligation and a date. Both need the right endorsement, and both give you a client relationship that renews itself every year.