Contractor Change Order Best Practices (+ Free Template, 2026)

The single most common source of contractor-client disputes is extra work that wasn't documented in writing. A change order prevents that dispute before it starts — and protects your margin on every addition to the original scope.

What a change order must include

• Reference to the original contract — date and project description
• Clear description of the change — what's being added, removed, or modified
• Cost change — the exact dollar amount added or deducted
• Time change — additional days added to the completion date, if any
• Signatures from both parties — client and contractor, before work begins
• Change order number — CO-001, CO-002 (sequential, for tracking)

The 5 change order rules every contractor must follow

1. No work before signing. If you start the extra work before the CO is signed, you're working for free — you have no legal obligation from the client.
2. Price it fully. Include labor, materials, any equipment, and your overhead and profit. Don't "do the client a favor" on extras — it trains them to expect it.
3. Add time in writing. If the change adds 2 days, add 2 days to the contract end date. This prevents "why aren't you done?" disputes.
4. Keep it numbered and filed. CO-001 through CO-whatever. Have a record for every contract.
5. Send a summary with the final invoice. Total original contract + total change orders = total amount due. No surprises on the final invoice.

Simple change order template

Change Order No.: _____
Date: _______________
Original Contract: [description], dated [date]
Client: _______________

Change Description:
[Describe what is being added/removed/changed]

Cost Change: + $_____ (adds to contract)
Days Added: _____
New Completion Date: _______________

Client Signature: _________ Date: _____
Contractor Signature: _______ Date: _____

How to handle verbal change requests

When a client asks for something extra verbally: "Happy to do that — I'll send you a change order for your approval before we start. Should take me just a few minutes." This makes it normal and professional, not confrontational.

ConstruMate has change order workflows built in — client signs the CO digitally before you touch the extra work. Try it free.

Start writing change orders the right way →