---
title: What Is a Change Order (CO)? Definition | Aavenir
url: https://aavenir.com/glossary/change-order-co/
description: A change order is a written, agreed change to the scope of work in an existing contract, which can also adjust its price, schedule or budget.
updated: 2026-11-07
---

[Home](https://aavenir.com/) / [Resources](https://aavenir.com/resources/) / [Glossary](https://aavenir.com/glossary/) / Change order Glossary

# What is a change order?

A change order is a written, agreed change to the scope of work in an existing contract, which can also adjust its price, schedule or budget.

## When change orders happen

Work rarely goes exactly to plan. A change order (CO) records a change to the original scope, and it can be started by the owner, a designer, a regulator or the contractor itself, for example when site conditions turn out different from what was expected. Change orders are most common in construction, but they appear in services and IT contracts too.

## What a change order includes

- The change to the scope of work.

- Its effect on price and budget.

- Its effect on the schedule.

- Who requested it and why.

- Signatures from the parties and the date approved.

## Why it matters

Change orders can be used with any contract type, whether fixed price, cost plus or unit price. Once approved and signed, a change order changes the budget. Untracked changes are a common cause of cost overruns and disputes, because nobody can say later what was agreed.

## How Aavenir handles it

[Contractflow](https://aavenir.com/solutions/enterprise-contract-management-software/) routes each change for approval, links it to the original contract and keeps the version history, so the current scope, price and dates are always clear.

## Keep reading

[Conformed contract A conformed contract is a clean copy of a contract that folds in every agreed change, so one document shows the current terms. Read more](https://aavenir.com/glossary/conformed-contract/)[Contract addendum A contract addendum is a document added to an existing contract that adds new terms or detail. Read more](https://aavenir.com/glossary/contract-addendum/)[Contract A contract is a legally binding agreement that sets out the rights and duties of the parties to it. Read more](https://aavenir.com/glossary/contract/)

Frequently asked questions (FAQ)

## Common questions

###

### What is the difference between a change order and a contract amendment?

A change order changes the work under the contract, usually scope, price or schedule, within a process the contract already allows. An amendment changes the contract's terms themselves. [Read about contract addendums](https://aavenir.com/glossary/contract-addendum/).

###

### Who approves a change order?

Whoever the contract names, usually the owner or buyer and the contractor or supplier, and often a project manager or designer. Internal approval rules may add finance for changes above a set value. [Read about contract approval](https://aavenir.com/glossary/contract-approval/).

###

### How do you keep track of change orders?

Number each one, link it to the original contract and record its effect on price and schedule. A conformed copy of the contract that folds in every approved change helps. [Read about conformed contracts](https://aavenir.com/glossary/conformed-contract/).

Have a question we have not answered? [Ask the Expert](https://aavenir.com/contact/)

Schedule a demo

## See your contracts run on one record.

- **1****A 30 minute walkthrough**Built around your team, whether that is procurement, legal, IT or finance.

- **2****Your contracts, not ours**Bring a few sample agreements and watch Aavenir AI extract and review them.

- **3****ServiceNow or standalone**We show the deployment that fits the systems you already run.

Prefer to talk first? [Contact the team](https://aavenir.com/contact/).

The form did not load. [Contact the team](https://aavenir.com/contact/) instead, or refresh the page.