What are change orders, and how to manage them without losing money
A client walks the job on a Tuesday and asks for one more outlet, a different light fixture, a wall moved eight inches. The crew lead says sure, because saying sure is the job. Nobody writes it down. The work happens Wednesday. Three weeks later the final invoice goes out for the original contract amount, because that is the number everyone remembers, and the extra work is gone — not unpaid exactly, just never billed at all.
This is the single most common way small contractors lose margin, and it has nothing to do with pricing or productivity. The work got done. The cost is real and already spent. The only thing missing is a piece of paper connecting the change to the invoice, and that piece of paper never existed because writing it up felt like it could wait until later. Later never comes.
Below: why verbal change orders disappear, how to capture one the moment it happens, and how to tie the extra cost to the job so it shows up in your margin instead of just your labor hours.
What is a change order?
A change order is a written agreement, signed by the contractor and the client, that changes the scope of work in the original contract. It records what is being added, removed or done differently, and what that does to the price and the schedule. Once signed, it becomes part of the contract.
Without one, the original contract is the only agreement anyone can point to. That is why an unwritten change is so risky: the work gets done, but on paper it was never agreed, never priced and never owed.
| Type of change order | What it means | Example |
|---|---|---|
| Additive | Adds work and raises the price. | The client asks for two more recessed lights. |
| Deductive | Removes work and lowers the price. | The client decides to supply their own appliances. |
| Hidden condition | Covers something nobody could see when the job was priced. | Rotted subfloor found under old tile. |
| Design change | The plans change after work is priced. | The architect moves a window opening. |
| No-cost change | Changes what is done but not the price. | Swapping one fixture for another of equal cost. |
Free construction change order form
A one-page printable form with every section above. See how to fill it in on the change order template page.
Why verbal change orders get built but never billed
A change order fails for a boring reason: the person who says yes to the client is standing on a roof or in a crawlspace, not sitting at a desk with a contract template open. Writing it up formally means stopping work, finding paper or a laptop, and doing office work in the middle of a physical job. So it gets postponed — mentally filed under a plan to write it up that night — and the postponement is where it dies.
By the time anyone is back at a desk, the exact request has blurred. Was it one outlet or two? Did the client agree to pay extra, or just nod when asked? A day later nobody is confident enough to bill it, so the safest move — from the crew's point of view — is to say nothing and let the work absorb into the job.
The cost of a missed change order is not just the unbilled labor and material. It is a full loss twice over: the job absorbed a real cost with no matching revenue, and the client learned that asking for extras on-site is free.
Capturing a change the moment it happens
The fix is not a better change order form. Most contractors already have a form; it just never gets filled out because filling it out is not something that happens naturally on a ladder. The fix is making the first step small enough to do in the moment, with the rest of the paperwork following later.
- The moment a client asks for something extra, note it right then — a phone photo of the spot, a one-line description, who asked, and a rough price if you can give one on the spot.
- Tell the client out loud that it is a change to the contract, not a favor. A short sentence telling them it is outside the original scope and you will get them a number is enough to set the expectation before the work starts.
- Get a yes before the material gets bought or the wall gets opened, even an informal one, so there is a moment of agreement to point back to.
- Turn the on-site note into a real change order the same day, while the details are still fresh, and send it to the client for a signature or a reply confirming the price.
- Code the added cost and the added revenue to the same job, so the change order shows up in the job's numbers rather than sitting in a separate folder nobody checks against the final invoice.
Tying change order costs to the job
A change order that lives in a separate email thread from the job cost is nearly as bad as no change order at all, because it is invisible at the moment that matters — when the final invoice gets written. The extra material and extra hours need to land in the same job cost as the original scope, so the total cost of the job includes everything that actually happened to it.
| Without linking the change order to the job | With it linked |
|---|---|
| Extra hours get logged to the job like any other hours, but there is no matching revenue to offset them. | Extra hours are tagged to the change order, and the change order carries its own price, so margin on the job reflects the full picture. |
| The final invoice is built from the original contract, and the change order is a separate document someone has to remember to add. | The change order total rolls into the job automatically, so billing it is not a step anyone can forget. |
| A job that looks like it lost money on paper may have actually broken even, once you account for extras nobody billed. | The job cost report tells the truth the first time, without a second pass to hunt for missed extras. |
A worked example
A $48,000 remodel is budgeted at $38,460 in cost, for a planned margin of $9,540, about 19.9%. Partway through, the client asks the crew to move a shut-off valve and add two recessed lights — a reasonable, common request, and one nobody thinks to formalize because it feels small in the moment.
The work costs roughly $1,400 in labor and material. If it never gets written up, the job absorbs that $1,400 with nothing to offset it — margin drops to about $8,140, or 17%, and nobody can say exactly why, because the job looks the same as it was bid.
Written up the same day and billed at $2,600 — the actual cost plus a normal markup — contract value becomes $50,600 against a cost of $39,860. Margin lands at $10,740, or about 21%. Same work, same crew, same client conversation that already happened. The only difference is whether the request got captured before it turned into unbilled labor.
A phone photo taken on-site is a start, but it only helps if the cost lands on the job. SiteLedger lets a receipt or an extra hour get tagged to a job the moment it happens, so a change order shows up in that job cost right away instead of surfacing as a surprise on the final invoice.
Common questions
- What are change orders in construction?
- Written agreements that change the original scope of a construction contract, along with the price, the schedule, or both. They are signed by the contractor and the client and become part of the contract.
- What is the biggest reason small contractors lose margin on change orders?
- Work gets approved verbally on-site, gets built, and never gets written up or billed because formalizing it feels like it can wait. The cost is real and already spent; the missing piece is a document connecting it to an invoice.
- How do I capture a change order without stopping work?
- Note it the moment it is requested — a photo, a one-line description, and a rough price if you can give one on the spot. Turn that note into a formal change order the same day, while the details are still accurate, rather than trying to reconstruct it later.
- Should change order costs be tracked separately from the original job budget?
- No. They should roll into the same job cost so the total reflects everything that actually happened on the job. Tracking them separately makes it easy for the extra cost to show up without the extra revenue ever catching up to it.
- Do I need a signed change order for every small request?
- For anything that adds real cost, yes, even informally — a text confirming the price is enough for a small item. The goal is a moment of agreement to point back to, not a full legal document for every extra outlet.
- How much does an unbilled change order actually cost a contractor?
- More than the missed revenue. The job absorbs a real cost with nothing to offset it, which quietly drags down margin on a job that otherwise looked fine, and it teaches the client that asking for extras on-site does not cost anything.
Keep reading
Free construction change order form, and how to fill it in
A free, printable construction change order form, with what goes in each box, how to price the change, and when to get the client to sign.
Job costing for contractors: how to know your margin before the job closes
How to tie labor, materials, subs and overhead to a job while it is still open, budget each bucket, and spot a job going bad early enough to fix it.
Markup vs margin: the difference that quietly costs contractors money
Markup is what you add to cost. Margin is what you keep. A 20% markup is a 16.7% margin — the arithmetic, a conversion table, and how to price backwards.
How to read a job cost report
How to read a job cost report: committed against actual, percentage complete against percentage spent, and the three numbers worth acting on.