A cost plan should price the work you intend to tender. Before issue, check that it matches the brief, drawings and specification so contractors can price the same scope.
Can another reader trace your budget back to the scope that was priced?

State What Was Priced
List the drawings, versions and price date used. Show the quantities and rate sources, with a clear note where an allowance or benchmark is used.
Include site costs, overheads and profit on the stated basis. Say how fees, VAT, inflation and other client costs are treated.
Give Each Gap A Next Step
For each allowance, state what it covers and which facts are missing. Keep known work apart from risk so the same cost is counted once.
If the plan exceeds the budget, show the gap. The team can then change scope, design or funds, rather than cut a sum without changing the work.
Your total may fit the budget. Does it price the same job as the tender pack?
- Basis
List the scope, versions and price date.
- Gaps
Show allowances, risks and missing facts.
- Movement
Explain changes and name the next action.
Use that same basis to check the tender returns and any proposed saving.
Explain The Move Since The Last Plan
Use the same cost breakdown to show changes in scope, quantities, rates and risk. Name who needs to act on each open point and by when.
Before tender, confirm that the pack and plan describe the same work. Keep that basis for the bid review so a lower offer can be judged on what it includes.
General guidance. Check your signed contract and the job facts. Get legal advice where needed.