What Is a Change Order and How to Write One
Almost every project changes once it starts. The client picks a different fixture, you find rot behind a wall, or the scope grows. A change order is how you handle those changes in writing, so everyone agrees on the new work, the new price and the new timeline before it happens.
What is a change order?
A change order is a written document that modifies the original agreement or estimate for a job. It describes what is being added, removed or changed, how that affects the cost and schedule, and it is signed by both the contractor and the client. Once signed, it becomes part of the project record and is referenced on the final invoice.
When do you need one?
- The client asks for extra work or upgrades not in the original scope.
- The client removes part of the work, which should reduce the price.
- Hidden conditions are found, such as damaged framing, outdated wiring or plumbing problems.
- Material substitutions are needed because the specified item is unavailable.
- Code or inspector requirements force a change.
- The schedule changes in a way that affects cost.
A good rule: if a change affects price, time or what the finished job looks like, write it down.
What to include in a change order
- Change order number and date. Number them in order for each project (CO-1, CO-2...).
- Project and client details, plus a reference to the original estimate or contract number.
- Description of the change: specific and plain, including what is added or removed.
- Reason for the change: client request, hidden condition, substitution, etc.
- Cost impact: labor, materials and any other costs for the change, and whether it adds to or reduces the price.
- Revised contract total: original amount, changes to date, this change, and the new total.
- Schedule impact: number of days added, or none.
- Payment terms for the change, if different from the original agreement.
- Signatures and dates from both parties.
How to write a change order, step by step
1. Stop and document
When a change comes up, pause that part of the work. Take photos, especially of hidden conditions, and write notes on what you found.
2. Describe the change precisely
"Additional electrical work" is too vague. "Install two new duplex outlets on the north kitchen wall, including wire, boxes and patching" is clear.
3. Price it the same way you priced the original job
Use the same rates and markup as the original estimate so the client sees consistency. Break out labor and materials.
4. Show the running total
Clients get uneasy when changes pile up without a clear total. Showing the original price, previous changes and the new total keeps everyone on the same page.
5. Get the signature before doing the work
This is the most important step. Verbal approvals are easy to forget or dispute. A signed change order (on paper or electronically) protects both sides. Some original contracts spell out how changes must be approved, so follow your agreement.
6. Reference it on the invoice
List approved change orders by number on the invoice so the final price is easy to trace.
Tips to avoid change order disputes
- Explain at the start of the job how changes will be handled.
- Write clear exclusions in the original estimate so additions are obviously additions.
- Use allowances for items the client has not chosen yet.
- Keep change orders short and specific; one change per form is easiest to track.
- Keep copies of every signed change order with the project file.
Example change order wording
Here is how a clear description might read: "Client requested upgrade from standard vanity to 48-inch double vanity. Adds cost of upgraded vanity and second faucet, plus additional plumbing labor to add a second drain and supply lines. Adds one working day to the schedule." Below that, list labor and materials with amounts, then show the original contract total, approved changes to date, this change and the revised total. It is short, specific and easy for the client to approve.
Change orders and allowances
If your estimate used an allowance, for example a set amount for light fixtures, the client's final selection may come in over or under that amount. A short change order records the difference so the final invoice matches what was agreed.
An editable one-page Word change order form with fields for the original contract, description of change, cost and schedule impact, and signatures.
Get it on Payhip: $4.99Frequently asked questions
Is a change order a contract?
A signed change order generally modifies the original agreement. How it is treated legally depends on your contract and local law; consult a local attorney if you are unsure.
Who signs a change order?
Both the contractor and the client (or their authorized representative). On larger projects, an architect or general contractor may also sign.
Can a change order reduce the price?
Yes. Removing work or switching to a cheaper material is a deductive change order, and the price should go down.
What if the client won't sign?
Do not perform the extra work until the change is agreed in writing. Discuss the options and document the conversation.
Should I charge for writing a change order?
Some contractors include an administrative fee in their terms; others build it into their rates. State your policy in the original agreement.