5 Plumbing Contracts Every Plumber Needs (With Free Templates)

Working without contracts is like plumbing without shut-off valves. Everything's fine until it isn't, and then the damage is catastrophic. Here are the five contracts every plumbing business needs.

1. Service Agreement / Work Authorization

This is your most-used contract. It should be signed before you start ANY work, even a simple service call.

What it covers: - Scope of work (what you're doing) - Price or pricing method (flat rate vs. time & materials) - Payment terms (when payment is due, accepted methods) - Basic warranty on your labor - Cancellation terms

Why it matters: Without a signed scope of work, the customer can claim you agreed to do more than you did. "I thought you were going to replace the whole faucet, not just fix it" becomes a he-said/she-said argument that you'll lose.

2. Warranty & Liability Agreement

Separate from your service agreement, this document specifically defines:

• What your warranty covers (labor for 1 year is standard)
• What it does NOT cover (misuse, pre-existing conditions, acts of nature)
• The limit of your liability (typically capped at the amount paid)
• Indemnification language protecting you from third-party claims

Why it matters: A customer whose basement floods three months after you replaced a water heater will blame you regardless of the cause. A warranty agreement with clear exclusions gives you legal standing.

3. Change Order Form

When the scope of work changes mid-job (and it always does), you need a written, signed change order before doing the additional work.

What it covers: - Description of additional work - Additional cost - Impact on timeline - Customer signature authorizing the change

Why it matters: "While you're here, can you also..." is how plumbers lose money. Change orders convert verbal requests into documented, billable work. Without them, customers will dispute charges for work they verbally asked for.

4. Proposal / Estimate

For larger jobs (remodels, repipes, water heater replacements), a detailed proposal shows professionalism and reduces disputes.

What it covers: - Detailed scope of work with line items - Materials list - Timeline - Payment schedule (e.g., 50% deposit, 50% on completion) - How long the estimate is valid (30 days is standard)

Why it matters: A professional proposal wins more jobs. When a homeowner gets three quotes and yours is the only one with a clear, detailed breakdown, you stand out. It also prevents "I thought the price included..." arguments.

5. Subcontractor Agreement

If you ever hire another plumber to help on a job, you need a subcontractor agreement.

What it covers: - Scope of their work - Pay rate and payment schedule - Insurance requirements (they should carry their own liability) - Who provides materials and tools - Non-compete / non-solicitation (so they don't steal your customers)

Why it matters: Without this agreement, a subcontractor injured on your job could become your workers comp claim. And a subcontractor who does poor work creates liability that falls on you, the general contractor.

Stop Working Without Paper

Yes, contracts feel formal. Yes, most of your customers are nice people who would never try to screw you over. But contracts aren't for the 95% of jobs that go smoothly. They're for the 5% that don't. And one bad job without a contract can cost you more than a year's worth of profit.

Every contract is a one-time setup. Write it once (or download a template), customize it with your company info, and use it on every job. Five minutes of paperwork before a job can save you months of stress after.