To handle a change order, stop and write it down before doing the extra work: describe the change, price it, show how it affects the schedule, and get the customer’s signature. Only then do the work, and bill it as its own line. The order matters more than anything else: priced and signed first, built second.
Most change order fights come from skipping that order: the customer asks for “one more thing” on site, the crew does it to be helpful, and the price shows up as a surprise on the final invoice. Here’s how to avoid that on every job.
The short answer
| Do | Avoid |
|---|---|
| Put the change process in the original contract | Agreeing to extras with a nod on site |
| Price the change before the work starts | Sending a bill for “extras” at the end |
| Show the schedule impact in days | Letting the finish date quietly slide |
| Get a signature (a phone signature counts) | Relying on a text that says “sure” |
| Collect payment for the change on your terms | Carrying every change until final payment |
| Log no-charge changes too | Doing free extras that leave no record |
Set it up in the contract
The easiest change order conversation is the one you already had at signing. Add a short clause to every quote or contract so the customer knows how changes work before any come up.
“Changes to the scope of work will be documented in a written change order that describes the change, its price and its effect on the schedule. No change will be started until the change order is signed by both parties. Approved change orders are payable [on signing / with the next progress payment].”
Also list your exclusions and allowances clearly in the quote (for example: “tile allowance $6 per sq ft”). Half of all change orders are really scope that was never defined. Our guide on how to write a contractor estimate covers how to define scope tightly.
The 7-step change order process
When a customer asks for something new, or you find something unexpected, say “Good catch, let me write that up as a change” before anyone starts.
Write what’s being added, removed or swapped, in plain words. Add photos if you found a hidden condition.
Labour, materials, equipment, subtrades, markup and tax. Credit any work it replaces.
How many working days it adds, and the new completion date.
Customer and contractor sign before the work. An e-signature on their phone is fine.
Only the signed scope. If it changes again, that’s a new change order.
Collect per the clause, or add it to the next invoice as its own line with the change order number.
What a change order must include
A change order is a small contract amendment. It should stand on its own if someone reads it a year later.
| Field | Example |
|---|---|
| Change order number and date | CO-2, November 3, 2026 |
| Original contract or quote reference | Quote Q-1042, signed October 6 |
| Customer and job address | Sarah Chen, 18 Birch Rd |
| Description of the change | Replace existing shut-off valves under sink and toilet with quarter-turn valves |
| Reason (optional but useful) | Customer request / hidden condition found when opening wall |
| Price breakdown | Labour, materials, markup, tax |
| Credit for removed work | Remove “reuse existing valves”: −$0 |
| Schedule impact | +1 working day, new completion November 14 |
| Revised contract total | Original + all approved COs to date |
| Payment terms for this change | Due on signing / with next progress payment |
| Signatures and dates | Customer and contractor |
Always show the running total: original contract, plus each approved change order, equals the new contract price. Customers who see the running total are rarely shocked by the final invoice.
How to price a change order
Price changes the way you price the original job, plus the disruption. Changes mid-job are less efficient: crews stop and restart, materials come in small orders, and the schedule shuffles. That cost is real, so include it.
| Worked example: add a pot light circuit to a finished basement | Amount (CAD) |
|---|---|
| Electrician labour, 6 hrs at $95 | $570.00 |
| Drywall patch and paint, 3 hrs at $70 | $210.00 |
| Materials (6 lights, wire, box, breaker) | $340.00 |
| Small-order delivery fee | $40.00 |
| Direct cost | $1,160.00 |
| Overhead and profit at 25% | $290.00 |
| Change order price before tax | $1,450.00 |
| HST 13% (Ontario) | $188.50 |
| Total for this change | $1,638.50 |
| Schedule impact | +1 working day |
These are worked-example rates, not a price guide; use your own labour rates and markup. If you’re not sure your markup covers overhead, read how to price a contractor job and check past jobs with job costing. Many contractors use a slightly higher markup on change orders than on the base contract because of the disruption.
How to talk about it with the customer
Customers don’t hate change orders. They hate surprises. Raise it on the spot, frame it as their choice, and give them the number before the work.
“Happy to do that. It’s outside the original scope, so I’ll write it up as a change order with the price and how many days it adds. You can look it over tonight and sign on your phone if you want to go ahead.”
“When we opened the wall we found the subfloor is rotted around the toilet flange. Here are photos. We can’t tile over it properly. I’ll send you a change order for the repair; it adds about a day. Want to take a look together now?”
“I get it. Here’s the breakdown so you can see where the number comes from. If it’s more than you want to spend, we can [option B] for less, or leave it out and finish as quoted.”
“Hi Sarah, here’s change order CO-2 for the new shut-off valves: $560 plus HST, adds one day. Tap to review and sign: [link]. We’ll do it as soon as it’s signed.”
Tricky situations
Safety or code issues
If you uncover something unsafe, make the area safe, take photos, and tell the customer right away. Write the change order immediately. If the fix truly can’t wait for a signature, get written approval by text or email at minimum, then follow up with the signed form.
The customer won’t sign
Don’t do the work. Finish the original scope, and note in writing that the customer declined the change. If the change is required to finish the original work properly (for example, a code issue), explain that in writing and pause that part of the job.
Small “while you’re here” favours
Decide your threshold. Plenty of contractors do 15-minute favours for free to build goodwill. Still write a no-charge change order so there’s a record, and so the customer knows it was a favour, not part of the scope.
Credits and deletions
If the customer removes scope, issue a change order with a credit. Credit your cost plus a fair share of markup, minus any materials you already bought or can’t return.
Rules that apply in some places
Change orders aren’t just good practice. For residential work, some jurisdictions spell them out:
- Ontario: the province’s guide for home renovation businesses says that when an estimate is part of the contract, you can’t charge more than 10% above it unless the customer asked for additional or different work and you both signed a change to the contract. It also says to document scope changes in writing and have both parties sign.
- California: the Contractors State License Board says changes to the price or scope of a home improvement contract must be made with a written change order signed by the customer and contractor before the change (CSLB: home improvement contracts).
- Everywhere else: even where no rule names change orders, a signed document is what you’ll rely on if a payment dispute ever reaches small claims or a lien.
General information, not legal advice. Check your province or state’s consumer protection and contractor licensing rules.
Getting change orders paid
Unbilled change orders are the most common way contractors leak profit on a job. Close the loop:
- Collect on signing for larger changes, especially when you have to buy materials.
- Otherwise, add each approved change order to the next progress invoice as its own line with its number.
- Keep a running total on every invoice so the final bill matches what the customer already approved.
- Check that nothing is billed twice when you build the final invoice.
See our contractor invoice template for how change orders appear on the bill, and how to get paid faster for the follow-up schedule.
In Contruva, change orders are part of the job: you price them with the days they add, the customer signs on their phone, and once signed they’re added to the bill, never twice. Job costing then shows what the job, changes included, actually made you. Try it with Contruva Pro, free for 7 days.