Change Order (CO)

A change order is a signed amendment to an existing engagement that authorizes work outside the original scope and adjusts the fee, timeline, or both.

It is the formal mechanism for managing scope changes without renegotiating the entire contract. Every piece of out-of-scope work performed without a signed change order is delivered at the firm’s cost with no authorization to bill for it.

What triggers a change order

A change order is required any time the engagement needs to deviate from the signed agreement:

• The client requests additional deliverables or workstreams not covered by the original scope
• The timeline extends because of client-side delays or unavailability
• Agreed assumptions prove incorrect, materially changing the effort required
• New stakeholders or systems are added to the engagement
• Regulatory or strategic changes require work the original scope did not anticipate

The test is simple: if the original engagement letter would not obligate the firm to perform the work, a change order is required before the work begins.

What a change order contains

• Reference to the original agreement it amends
• Description of the change: what is added, removed, or modified
• Additional fee or revised total fee
• Revised timeline or milestone dates
• Impact on any existing deliverables or milestones
• Signatures of authorized representatives on both sides

Why discipline here matters

Every instance of out-of-scope work performed without a signed change order erodes margin. Over a year, small absorptions compound. Firms that track realization rate by engagement can see exactly where unmanaged scope changes are reducing profitability.

The practical barrier is cultural: delivery teams often absorb small requests to avoid friction with clients. A clear, low-friction change order process makes raising one easier than ignoring the request.

Requiring a change order also protects the client. It forces explicit discussion of the cost and schedule impact before work begins, which prevents the end-of-project surprise where both parties disagree over what was in scope and what was an addition.

Change orders and the change log

Each signed change order should generate an entry in the change log, which tracks cumulative scope and budget movement across all changes on the engagement. The change log is the audit trail; the change order is the authorization document for each individual change.