Understanding changes to your subcontract work
A changed task can affect quantities, sequence, resources and completion. Record the change first, then follow the process in your particular subcontract.
By Jack Butler-Kettle · Updated
Guidance for England and Wales. Check the contract, amendments and facts that apply to your job.
The short answer
Compare the instructed work with the agreed scope. Identify who can instruct a change, which notices are needed and how it is assessed. Extra work does not establish its own contractual entitlement or price.
Describe what changed
Record the original requirement, revised requirement, instruction date and person giving it. Keep drawings with their revision numbers.
Separate additional quantity from changed specification, access restrictions and altered sequence. Each may need different evidence or a different contractual route.
If an instruction is verbal, create a timely written record and follow any contractual confirmation procedure. A record does not replace a required notice.
Follow the correct process
JCT and NEC use different mechanisms, and their forms vary. Compare the families in JCT or NEC, then check your signed terms.
NEC treats early warning and compensation-event processes separately. An early warning can help manage risk without itself notifying a compensation event.
The NEC explanation of linked processes shows how they interact. Its main-contract roles must be adapted to your subcontract.
Record effects without assuming entitlement
Keep quantities, labour, plant, materials and subcontract costs traceable to the changed activity. Distinguish forecast amounts from actual expenditure.
Record programme effects separately. More labour cost does not itself prove a completion delay, and more time does not automatically establish extra payment.
Explain your assumptions and avoid counting the same resource twice. Identify work avoided as well as work added.
Keep a change register
Use one line per change with an identifier, instruction, notice deadline, submission, assessment and current disagreement. Link each line to its evidence.
An NEC deadline copied from a main contract may be wrong for a subcontract. NEC distinguishes their notification periods.
Check the applicable trigger, exceptions and amendments. This is general learning for UK subcontractors. Check your governing law, contract form and amendments. Statutory procedures differ across England, Wales, Scotland and Northern Ireland.
Example
Fictional example, not a client result. Figures are simplified to explain the point.
The facts
A drylining subcontractor is instructed to move a partition after first-fix work has started.
What happens
It saves the original and revised drawings and records the instruction.
It separates demolition, replacement materials and labour from any claim concerning altered sequence.
It checks the subcontract notices and submits its assessment with assumptions and supporting records.
What this shows
The change has a traceable account of scope and effects. Agreement on the instruction does not automatically establish the submitted price.