How to Write a Plumbing Estimate Customers Can Approve

The checklist

1. Your business details: name, address, phone, and your license number where your state requires it (see the last section).
2. Customer, job address, date and an estimate number you can refer to on change orders and the invoice.
3. Scope of work, written so someone who wasn't on the call could tell what's included.
4. Options, each priced as a complete job.
5. Exclusions and assumptions.
6. Price, with any sales tax shown the way your state expects.
7. Expiry date.
8. Deposit and payment terms.
9. How changes are handled (change orders).
10. Signature and date lines and, for covered in-home sales, the cancellation statement and forms.

Scope, options and exclusions

Scope

Write the scope as a list of tasks and materials, not a headline. "Replace 50-gallon gas water heater" leaves open the make and model, the venting, the expansion tank, the shutoffs and connectors, the permit and what happens to the old tank. Name each piece that is part of the price, with make and model, or "or equal" where you allow a substitute.

Options

Options let the customer choose without asking you to re-quote. Price each option as a full job — labor, materials, permit, disposal — rather than as an add-on to option one, so nobody adds them up wrong. Build every option the same way: standard hours at your shop rate plus materials at your markup. The flat-rate price calculator does that per task, and flat rate vs time and materials covers when to quote a fixed price and when to quote by the hour.

Exclusions and assumptions

Say what the price does not cover and what you're assuming. Lines that come up on plumbing work:

• Drywall, tile, flooring or paint repair after access openings.
• Work the inspector or local building department requires beyond the listed scope, priced as a change order.
• Conditions hidden inside walls, floors or the ground until they're opened.
• Access assumptions: crawlspace height, attic access, items the customer will move.
• Permit fees, if you bill them separately.

Price, tax and expiry

Show the total the customer will pay. Whether you add sales tax, and on what, depends on your state and on how the contract is written; do plumbers charge sales tax walks through what several state revenue agencies say. Paperwork matters here too. For custom construction, the Washington State Department of Revenue says a bid or contract should show sales tax as a separate amount, that wording such as "sales tax included" does not count as separately stating it, and that it presumes a quoted price does not include tax unless the tax is itemized.

Give the expiry as a date ("valid through November 3, 2026"), not "valid 30 days" with no start. Material prices and your schedule both move; an expiry date gives you a clean reason to re-price instead of honoring a number you built months ago.

Deposits, payment terms and change orders

Deposit. State the amount, when it's due, what it covers (special-order equipment, for example) and whether any part is refundable. State law can cap deposits. California's Business and Professions Code section 7159.5, which applies to home improvement contracts as that code defines them, limits a down payment to $1,000 or 10% of the contract amount, whichever is less. On a $6,400 contract that's $640; on a $15,000 contract it's $1,000. The same section requires a schedule of progress payments in dollars and cents if you take payments before completion, and bars taking payment, other than the down payment, beyond the value of work performed or materials delivered. Contractors who furnish certain approved bonds are exempt from those three limits. Check your own state before you set a standard deposit.

Payment terms. Say when payment is due (on completion, or by stage on larger jobs), which methods you accept, and any card surcharge or cash price. Card surcharges come with network rules and state limits; see credit card fees for contractors before you print one. The deposits and payment terms guide works the deposit, progress-payment and late-fee math; ask your attorney before you put late fees or interest on an estimate.

Change orders. Any change in scope or price gets written down, priced and signed before the extra work starts. Reference the original estimate number and show the new total, so the final invoice matches paper the customer already signed. Change orders for trade jobs shows how to price one.

In-home sales and the FTC Cooling-Off Rule

The FTC's Cooling-Off Rule, 16 CFR Part 429, covers sales of consumer goods or services of $25 or more made at the buyer's home, including when the buyer invited you, and $130 or more at other places away from your place of business, such as the buyer's workplace. Consumer goods and services are those bought mainly for personal, family or household use, so commercial work falls outside it. For a covered sale, the seller must:

1. Give the buyer a completed, dated receipt or contract in the same language as the sales presentation, with the seller's name and address.
2. Print, next to the buyer's signature line (or on the front page of the receipt if there is no contract) in bold type of at least 10 points, a statement that the buyer may cancel before midnight of the third business day.
3. Give the buyer two copies of a completed Notice of Cancellation form with your name and address, the transaction date and the cancel-by date.
4. Tell the buyer about the right to cancel out loud.
5. If the buyer cancels, refund all payments within 10 business days.

Business days exclude Sundays and federal holidays; Saturday counts. The FTC's consumer guide gives the example of a Monday sale in a week with no holiday: the buyer has until midnight Thursday. A job sold on a Friday before a Monday holiday can be cancelled until midnight Wednesday. If you start non-emergency work inside that window and the buyer cancels, you still owe the full refund.

Two exclusions matter to plumbers:

• Emergencies. Excluded only when the buyer started the contact, the need is a genuine immediate personal emergency, and the buyer gives you a separate statement, in their own handwriting, dated and signed, that describes the emergency and waives the three-day right. The rule also bars putting a waiver of the cancellation right into the contract or receipt itself, so a pre-printed waiver box doesn't do it.
• Requested repairs. Excluded when the buyer asked you to the home to repair or maintain the buyer's personal property. Anything you sell beyond the replacement parts that repair needs (a water softener, a service plan, a second job) falls outside the exclusion. The exclusion is written for the buyer's personal property; if you plan to rely on it for work on the house itself, ask an attorney first.

The federal rule leaves state door-to-door laws in place unless they conflict with it, for example by giving buyers a weaker right to cancel, so your state may add requirements of its own.

License numbers and other state rules

Some states require your license number on the paperwork itself. California's section 7030.5 requires it in all construction contracts, subcontracts and calls for bid, and in advertising. Florida's section 489.119(5)(b) requires the registration or certification number on each offer of services, business proposal, bid, contract or advertisement. Rules differ by state and by license type, so check with your state licensing board; printing the number in your estimate header puts it on every estimate you send.

This is general information, not legal advice. For contract terms, deposits and cancellation notices in your state, ask an attorney and your licensing board.

Next step

Open the estimate generator and lay out one of your common jobs against this checklist: a full scope, two or three complete options, your standard exclusions, an expiry date and your deposit terms. Keep that exclusions block and reuse it, edited per job, on every estimate you write. If you want estimates, invoices and card payments in one app, the cheapest way to estimate and invoice prices the options for a one-truck shop.