Describe the difference
Reference the original project and state what is being added, removed, or replaced. Use the same concrete language used for deliverables.
Include assumptions and dependencies that affect the estimate.
Show commercial impact
State the added or reduced fee, tax treatment if relevant, payment timing, and any change to delivery dates.
If the request affects other deliverables, identify those consequences directly.
Require approval
Name the person authorized to approve and the date through which the estimate remains valid.
Do not begin changed work until approval is recorded. Attach the change to the project record.