Contract amendment vs. change order

Both documents change a live contract, but they operate at different levels: a change order adjusts the work, price or schedule under the change mechanism the contract already contains, while an amendment modifies the contract instrument itself — terms, duration, parties or other foundational elements.

What it is

In Canadian construction practice, the contract itself sets out the process for negotiating variations of the scope of the work, and change orders are the standard instrument for exercising that process while the project runs: they direct added, deleted or modified work and adjust the price or schedule within the contract's existing frame. An amendment goes further — it alters the agreement itself. In the federal context, the Office of the Procurement Ombudsman's review of construction contract amendments treated amendments as formal changes to the contracting instrument that departments must approve and issue in accordance with their documented policies and delegations, with complete records on file showing the decision-making process. Public Works and Government Services Canada (now Public Services and Procurement Canada), which awarded approximately $700 million in construction contracts and managed roughly 1,800 new construction contracting instruments annually at the time of that review, manages both changes and amendments through a dedicated contracting unit — with delegated construction contracting authorities for most other federal entities historically no greater than $400,000.

How buyers treat each differently

The OPO review found that federal organizations split responsibility: project or property managers handle day-to-day project decisions while procurement or contracting officers administer the contract — so a change order is typically processed by the project side under pre-approval mechanisms and contract risk assessments designed to enable prompt decisions during the work, whereas amendments route through the contracting authority with formal approvals. Some organizations handle lower-dollar-value changes less formally, while others apply identical rigor to all changes regardless of value. For suppliers, the practical consequences: a change order keeps you working within the original terms; an amendment can move you onto new terms — different payment provisions, extended delivery periods, revised security requirements — so read the whole amendment, not just the price line.

What it means for vendors

Watch two things on any federal or municipal construction job. First, authority: confirm the person directing the change actually holds delegated authority for its value — a change outside the delegations can be challenged or be unenforceable. Second, the ceiling: price and schedule changes accumulate, and both change orders and amendments count against the contract ceiling; if the cumulative value approaches the original contract value, expect the buyer to demand a formal amendment (or a new solicitation) rather than another change order. Keep your own file mirror-image of the buyer's — the OPO expected complete amendment files, and disputes turn on whose record is fuller.

Common questions

Is a change order a contract amendment?

Functionally no: a change order is issued under authority the contract already grants, while an amendment rewrites the contract itself. Terminology varies by contract — read the change-management clauses in your agreement rather than the document's title.

How is this different from an addendum?

An addendum modifies the solicitation documents before contract formation; amendments and change orders operate after a contract exists. See our addendum vs. amendment definition.

Can an amendment increase the contract without competition?

Amendments must stay within the scope of the original contract and the buyer's delegations; work outside the original scope can require a new competitive process. Trade agreement thresholds and internal policies govern the limits.

Related definitions

Change order · Addendum vs. amendment · Contract ceiling · Firm fixed price contract