A variation is a change in scope, executed under the contract's variation mechanism, priced using the contract's pricing regime (contract rates, star rates, dayworks, or cost-plus depending on the form), and settled through the normal certification cycle. A claim is a demand for entitlement to time or cost arising from an event that is not necessarily a scope change — it might be an employer-caused delay, a change in condition, a breach, or a disruption event.
The two categories overlap in practice. Many events start as variations and become claims. Some events are treated as variations that should have been claims. Some are treated as claims that should have been variations. Getting the categorization right matters commercially — because the recovery mechanism, the notice regime, the time bar, the pricing methodology and the substantiation requirements all differ.
Start with the contract's own definitions
The starting point is always the contract. FIDIC defines Variations under Clause 13 (1999) or the equivalent in later editions. NEC treats change through the Compensation Event mechanism. JCT uses Variations. Bespoke EPC forms often define both variations and claims separately, with different procedural requirements for each.
The contractual definition determines the recovery mechanism. If the event fits the variation definition, the variation mechanism applies. If it doesn't, the claim mechanism applies. Getting this wrong at the outset — treating a claim event as a variation or vice versa — usually costs entitlement, because it means the wrong notice regime and the wrong time bar are engaged.
The instruction test
The clearest indicator that an event is a variation is that it was instructed. If the Employer's Representative (Engineer, PM, or equivalent) has issued a written instruction directing a change in scope, method, sequence, or quality — that is a variation event, and the variation mechanism applies.
The absence of an instruction does not necessarily mean the event is a claim rather than a variation. Sometimes contractors execute scope changes on the basis of drawings, RFI responses, or verbal instructions, then discover after the fact that no formal instruction was issued. In these cases the correct approach is usually to seek confirmation of the instruction (or seek a formal instruction confirming what has been executed), and treat the event as a variation. Failing that, the fallback position is to treat the event as a claim under the applicable clause — but this is a weaker position because it has to argue that the scope change was a proper contractual event.
The time-impact test
If the event impacts time as well as cost, the treatment often bifurcates. The cost impact is treated as a variation (using the variation mechanism). The time impact is treated as a claim (using the extension of time mechanism). The two run in parallel with different substantiation requirements.
This is where contractors most commonly leak entitlement. The commercial team treats the event as a variation, gets the cost impact certified, and never notifies the time impact under the EOT mechanism. Six months later, the LDs are being calculated on a completion date that should have been extended, and the entitlement is time-barred.
The remedy is procedural: every variation with time impact is also notified as an EOT claim, in parallel, with cross-reference. This is standard practice on well-run contractor-side commercial functions and quietly disastrous when it's missed.
Prolongation and disruption are usually claims, not variations
Prolongation costs (time-related overheads incurred because the project was extended) are almost always recovered as claims, not as variations. Even where the variation caused the prolongation, the prolongation cost is typically substantiated separately as a claim linked to the extension of time, not as an element of the variation quantum.
Disruption costs (loss of productivity) are similarly usually claims. Even where the disruption arose from variations, the disruption analysis is typically a claim-based methodology (measured mile, productivity factors) rather than a variation-based one (contract rates, star rates).
Getting this right matters because prolongation and disruption require different substantiation methodologies than variations. Treating them as variations often means they get priced with the wrong methodology and rejected on substantiation grounds.
When to seek a formal position from the Engineer
Where the categorization is unclear — is this a variation or a claim, is it both, is it neither — the correct approach is usually to seek a formal position from the Engineer under the contract's determination mechanism. Under FIDIC that means engaging Sub-Clause 3.5 (1999) or the applicable clause. Under NEC it means using the Compensation Event mechanism to force a position.
Contractors that avoid engaging the determination mechanism because they're worried about relationship consequences often lose entitlement they could have recovered. Contractors that engage it routinely, professionally and without hostility usually preserve entitlement without damaging the relationship. Discipline is not hostility.
Register everything
Whatever the categorization, register the event. Change register, claim register, variation register — the format matters less than the discipline of capturing the event. The two most common failure modes we see: events that go unregistered because the commercial team is uncertain how to categorize them, and events that get registered on one register but not another, so the double-tracking (variation cost, EOT time) is lost.
The remedy is a consolidated event register that captures every event, with categorization applied deliberately. Events can be reclassified later as facts develop. What cannot be recovered is entitlement lost because the event never made it onto any register at all.