Contract Options

NEC Option A vs Option C: where the misapplication trap lives

Option A is not a fixed price. Option C is not cost reimbursable. The two most-used NEC Options on UK infrastructure are also the two most-misapplied. The misapplication is rarely caught at procurement. It surfaces in the numbers, six months in.

13 April 2026 · 9 min read · Free to read

Executive summary

If you ask ten people on a UK NEC programme to define Option A, half will say “fixed price.” If you ask the same ten about Option C, half will say “cost reimbursable with a cap.” Both descriptions are wrong, and the wrongness is not academic. It changes what the contract rewards, what it punishes, and where the team should be putting attention.

This post sets out what each Option actually says, what it actually rewards, and where the misapplication shows up, usually as a slow margin leak that no one notices until the cost report at month six.

Clause analysis

The contract options clause analysis

Option A: priced contract with activity schedule

The Contractor is paid the price for each activity once the activity is complete. The Activity Schedule is the basis of payment, not just the basis of pricing. Compensation events change the Prices by adding new activities or by changing existing ones, with the change assessed using Defined Cost plus Fee under clause 63 and the Schedule of Cost Components.

What that means in practice: Option A rewards activity-schedule discipline. The detail with which activities are defined determines the granularity at which the contract pays, and the granularity at which CEs are assessed. Lump-sum thinking destroys both.

Option C: target contract with activity schedule

Option C is two contracts running in parallel. The Contractor is paid Defined Cost plus Fee, monthly, against the actual cost of the work. At each assessment date, the total of those payments is compared against the target (the original Activity Schedule total adjusted for accepted CEs). The difference, under or over, is shared between the parties under the agreed pain/gain mechanism.

What that means in practice: Option C rewards two behaviours simultaneously: disciplined cost capture (the Defined Cost half) and disciplined target maintenance (the CE half). One without the other breaks the model.

Defined Cost and the Schedule of Cost Components

Both Options use Defined Cost for CE assessment. Under Option A, Defined Cost only matters when CEs are assessed. Under Option C, Defined Cost is the contract’s payment mechanism: every month, every line, every people-cost component. The discipline required is an order of magnitude higher.

Commercial implications

What it means on a live programme.

The misapplication trap is rarely caught at procurement. It surfaces six months in, in the numbers. Under a misapplied Option A, the Contractor takes lump-sum positions on CEs that should have been built up under the SCC, leaks margin on every event, and tells itself the events are “small.” Under a misapplied Option C, the Contractor lets the target drift because every CE goes through with low scrutiny, and discovers at the gain/pain reconciliation that the target it was working against bears no relation to the work that was done.

In both cases, the contract is doing what it was designed to do. The team is doing something different.

Failure modes

Where this fails in practice.

Option A treated as a lump-sum fix. CE quotations submitted as round numbers without SCC build-ups. Margin leaked on every event because the assessor has nothing to defend.
Activity Schedule too coarse. Twelve activities for a £20m package. Payment can’t be claimed until each one completes; the cash profile collapses.
Option C treated as cost-plus. The Contractor stops scrutinising CEs because every cost is reimbursed monthly anyway. The target drifts; the gain/pain reconciliation later wipes the margin.
Pain/gain not tracked monthly. The first reconciliation happens at the end of year one. By then the position is unfixable.
SCC categories misallocated. Subcontract costs accounted as People; Plant booked through the wrong sub-component. Defined Cost is later reduced under audit.
Disallowed Cost ignored. Under Option C, costs that meet the Disallowed Cost definition are still paid through. They are recovered out of the next pain/gain reconciliation, usually at the worst possible moment.

Key points

What good looks like.

Activity Schedule discipline (Option A). Activities defined at the level the team actually delivers, typically 3–5× more granular than the priced submission. CEs build up against the SCC, not against round numbers.
Target-cost behaviour (Option C). Every CE assessed with the same scrutiny as Option A. The target moves only when the contract says it does.
Monthly pain/gain reconciliation (Option C). A standing item on the cost report: actual Defined Cost vs adjusted target, this period and cumulative, with movement explained.
SCC categorisation rules agreed in week one. A short written paper from the Contractor’s commercial lead, accepted in writing by the PM, mapping the team’s ledger codes to the People / Equipment / Plant / Subcontracted Work categories. Stops 80% of later disputes on Defined Cost.
Disallowed Cost reviewed monthly (Option C). Not at year-end. Anything that meets the Disallowed Cost definition is identified at the next assessment date and explicitly excluded.
One EW register across both Options. The contract’s risk discipline is the same regardless of the payment mechanism.

Practical takeaway

The discipline that compounds.

The choice between Option A and Option C is a procurement decision; it is made once and rarely revisited. Misapplying the chosen Option is a delivery decision; it is made hundreds of times across the life of the contract. Most of the value destroyed under NEC is the second category, not the first.

Future posts in this theme will go deeper on the SCC, the pain/gain mechanism, and the activity-schedule trade-offs that decide a programme’s cash profile. Subscribe to get the next post the morning it ships.