A loss and expense claim JCT contract entitles a contractor to recover direct financial loss caused by disruption to the regular progress of the works - costs that fall outside the normal valuation of the contract sum. Get the process wrong, and even a rock-solid entitlement can evaporate on a technicality.

Under the JCT Standard Building Contract (SBC), the mechanism sits in clauses 4.20 to 4.23. It is deliberately procedural: the contractor must identify a qualifying Relevant Matter, apply in writing at the right time, and then substantiate the figures well enough for the quantity surveyor or Contract Administrator to ascertain them. Miss any one of those steps and the claim can be time-barred, regardless of how genuine the underlying loss is.

This guide walks through the process in the order a commercial manager or QS would actually run it on a live project: what loss and expense is, which Relevant Matters qualify, how and when to apply, what evidence stands up to scrutiny, how the assessment side works, where loss and expense differs from an extension of time claim, and the reasons claims most commonly get knocked back.

Whether you're building your first application or reviewing a subcontractor's submission before it lands on your desk, the aim is the same: turn a disrupted programme into a properly ascertained, defensible sum - not a dispute.

Quick Answer

A loss and expense claim under JCT lets a contractor recover direct financial loss caused when the regular progress of the works is materially affected by a listed Relevant Matter (clause 4.21) - provided the contractor makes a written application as soon as the effect becomes apparent (clause 4.20.1) and gives the quantity surveyor enough detail to ascertain the amount (clause 4.20.2). It is separate from - but often runs alongside - an extension of time claim, which addresses programme, not money.

What Is Loss and Expense Under JCT?

Loss and expense is the JCT mechanism for compensating a contractor for direct financial loss that isn't already recovered through the normal valuation of variations or other contract sum adjustments. It typically covers costs such as extended site establishment, prolonged supervision, plant standing idle, additional financing charges, head office overheads calculated using an accepted formula, and loss of profit where regular progress has been disrupted.

The current numbering sits under clauses 4.20 to 4.23 of the JCT Standard Building Contract 2016 (the equivalent clauses appear, renumbered, in the 2024 edition and across the Design and Build, Intermediate and Minor Works forms). Clause 4.20 sets the conditions precedent; clause 4.21 lists the qualifying Relevant Matters; clauses 4.22 and 4.23 deal with how the amount is ascertained and paid.

Crucially, loss and expense is not a bonus or a negotiated settlement - it's a contractual entitlement that has to be proven. The contractor carries the burden of demonstrating both that a Relevant Matter occurred and that it caused a specific, quantifiable loss. Without that causal link, even a legitimate grievance won't convert into a valid claim. That burden of proof sits squarely with the contractor throughout the process - the employer's team is under no obligation to build the case on the contractor's behalf, and a QS who spots a gap in the causal chain is entitled to ask for more evidence rather than fill the gap themselves.

Site manager and QS discussing a delayed work sequence caused by late information

The Relevant Matters: What Actually Qualifies

The closed list under clause 4.21

JCT deliberately limits the grounds for a loss and expense claim to a closed list of Relevant Matters - the contractor cannot claim simply because a project has become unprofitable or because progress slowed for reasons outside that list. The Relevant Matters broadly track situations where the employer, or someone the employer is responsible for, disrupts progress.

Table 01 / Relevant Matters under JCT SBC clause 4.21

Eight Relevant Matters give a JCT contractor grounds to claim loss and expense

Relevant MatterWhat it covers
Employer instructions (variations, provisional sums)Changes issued under clauses 3.14-3.16 that disrupt planned sequence
Late instructions or informationArchitect/CA fails to release drawings, details or instructions when due
Opening up and testing (clause 3.17)Work found to comply, but progress was disrupted by the investigation
Employer's failure to give access or possessionSite, or part of it, not handed over as the contract required
Suspension by the contractor (clause 4.14)Valid suspension for non-payment that then delays regular progress
Antiquities (clause 3.22)Discovery halts work in the affected area pending instructions
Employer's persons on siteOther contractors or statutory undertakers directly engaged by the employer
Deferment of possession / approximate quantitiesLate possession or quantities that are not a reasonably accurate forecast

Source: JCT Standard Building Contract clauses 4.21 and 4.23; Designing Buildings, "Loss and Expense."

Note the distinction between a Relevant Matter and a Relevant Event. Relevant Events (clause 2.29) justify an extension of time - they protect the contractor from liquidated damages. Relevant Matters (clause 4.21) justify a claim for money. Several circumstances - a late instruction, for example - appear on both lists, which is exactly why time and money are often claimed together but assessed separately.

Making the Written Application: Timing and Content

The two conditions precedent

Clause 4.20 sets out two conditions the contractor must satisfy before any entitlement crystallises. First, the contractor must make its application as soon as it has become, or should reasonably have become, apparent that regular progress has been or is likely to be materially affected. Second, the application must include, or be followed promptly by, sufficient information to allow the quantity surveyor or Contract Administrator to ascertain the loss and expense.

Courts and adjudicators have consistently treated these as conditions precedent rather than mere procedural formalities - meaning a late or vague application can extinguish an otherwise valid entitlement entirely. "As soon as" is not a fixed number of days, but the safer discipline is to notify within days of the disruption becoming apparent, not weeks after the event has passed.

  • Identify the specific Relevant Matter relied on, by clause reference
  • Describe how regular progress has been or is likely to be materially affected
  • State, where possible, an initial estimate of the loss and expense likely to be incurred
  • Reference the operations, work sections or activities affected
  • Commit to following up with detailed substantiation within a stated period

Many contractors submit an initial notice quickly to protect the entitlement, then follow with a fuller quantified application once the disruption has run its course and costs can be measured with more confidence. That two-stage approach satisfies clause 4.20 without forcing premature, unreliable numbers onto the record.

Substantiating the Claim: Records, Causation, Quantification

An application is only as strong as the evidence behind it. Ascertainment under JCT is meant to be a factual exercise - establishing what was actually lost - rather than a formula-driven estimate, so the quality of contemporaneous records is what usually decides whether a claim succeeds or gets discounted.

Records that carry weight

  • Programme and progress records showing planned versus actual sequence, ideally with a critical path analysis
  • Site diaries, daily allocation sheets and labour/plant returns for the affected periods
  • Correspondence and instructions that establish the Relevant Matter and its date
  • Delay event logs cross-referenced to specific activities and cost codes
  • Invoices, timesheets, plant hire records and subcontractor accounts for the actual additional cost incurred
  • Photographic and drone survey evidence of idle plant, standing labour or blocked work fronts

Establishing causation, not just correlation

The hardest part of any application is demonstrating that the Relevant Matter, and not some other concurrent cause, actually produced the loss claimed. A global claim - lumping all cost overrun into one figure and inviting the employer to disprove it - is treated with suspicion by adjudicators and the courts, and is far more likely to be rejected or heavily discounted than a claim that ties each cost element back to a specific event on a specific date.

Contractor's commercial team reviewing site diaries and cost records to substantiate a loss and expense application

How the QS or Contract Administrator Assesses a Claim

Once an application lands, the quantity surveyor (or the Architect/Contract Administrator directing the QS) has to ascertain - not simply agree or estimate - the loss and expense. RICS practice guidance describes ascertainment as establishing the actual loss suffered, evidenced by real cost data, rather than applying a rule-of-thumb percentage uplift.

  • Checking that the claim relates to a genuine Relevant Matter, correctly identified and dated
  • Testing whether the application was made in time to satisfy clause 4.20.1
  • Reviewing the causal link between the event and each cost claimed, activity by activity
  • Checking for double recovery - costs already priced into variations, dayworks or other contract sum adjustments
  • Adjusting for the contractor's own contribution to the delay (concurrent delay principles)
  • Issuing an interim ascertainment where full substantiation isn't yet available, with a clear basis recorded

Where the contractor's own information is inadequate, the QS is entitled to ask for more before ascertaining a figure - but cannot simply ignore an otherwise valid application because the paperwork is imperfect. Good practice on both sides is an open dialogue: QS and commercial manager working through the substantiation together, rather than a one-shot submission followed by silence.

Quantity surveyor cross-checking a loss and expense application against site records and cost codes

Loss and Expense vs Extension of Time: Related but Distinct

It's a common misconception that winning an extension of time automatically secures loss and expense, or vice versa. They are governed by separate clauses, separate tests, and - critically - separate notice requirements.

  • Extension of time (clauses 2.26-2.29) relieves the contractor of liability for liquidated damages by extending the completion date
  • Loss and expense (clauses 4.20-4.23) compensates the contractor financially for disruption
  • A contractor can be awarded an EOT but remain time-barred from loss and expense if the separate clause 4.20 notice wasn't given
  • Some events are both a Relevant Event and a Relevant Matter (e.g. late instructions); others sit on only one list
  • Best practice is to keep the two submissions procedurally distinct, even when they're issued around the same time, so neither argument is diluted by the other

Graphic 01 / Why loss and expense claims fail

Weak notices and poor records sink more claims than the underlying entitlement ever does

Late or missing written application under clause 4.21High risk
High risk
Insufficient detail to let the QS ascertain the lossHigh risk
High risk
Global claim with no cause-and-effect link per eventMedium-high risk
Medium-high risk
Overlap with EOT claim not separated outMedium risk
Medium risk
No contemporary records kept on siteMedium risk
Medium risk
Contractors that lose loss and expense entitlement most often do so on process grounds - a missed notice or a thin substantiation - not because the underlying Relevant Matter didn't occur.

Source: analysis of common grounds for rejection cited by Foot Anstey, Beale & Co and RICS practice guidance on ascertaining loss and expense.

In practice, many commercial teams run EOT and loss and expense as parallel workstreams sharing the same underlying records, but submitted and assessed as two distinct applications - one against clause 2.29, one against clause 4.21 - to avoid either being weakened by conflation with the other.

Common Reasons Loss and Expense Claims Are Rejected

Most rejected claims fail on process rather than principle. Recognising the common failure points before submitting an application - or before reviewing one from a subcontractor - is the fastest way to protect entitlement.

  • Late notice: the application wasn't made as soon as the effect on progress became, or should have become, apparent
  • Global claims: costs presented as one lump sum with no attempt to link individual events to individual losses
  • Insufficient substantiation: no contemporary records, or records that don't tie back to the Relevant Matter claimed
  • Confusing cause and effect: claiming for delay caused by the contractor's own resourcing or design issues, not a qualifying Relevant Matter
  • Double counting: claiming costs already compensated through variation valuations or other adjustments
  • No follow-through: an initial notice sent and never followed with the detailed information clause 4.20.2 requires

Where a claim is rejected in whole or in part, the contractor's remedy is the same as for any other contractual dispute - negotiation, mediation, adjudication or, ultimately, arbitration or litigation depending on what the contract specifies. Adjudication is by far the most common route given its statutory 28-day timetable, but a claim that was weak on notice or substantiation at first submission rarely improves simply by escalating it. It is far cheaper, in both time and legal cost, to fix a weak application before it's submitted than to fight for the same money in adjudication six months later.

Practical Tips for QS and Commercial Managers

Whether you sit on the contractor's or the employer's side of the table, a handful of habits consistently separate claims that get paid from claims that get argued over for months.

  • Build a live delay and disruption register from day one - don't try to reconstruct it retrospectively
  • Issue notices the moment disruption becomes apparent, even in short form, then follow up with full substantiation
  • Keep loss and expense submissions separate from EOT submissions, even when the underlying facts overlap
  • Cost-code labour, plant and preliminaries so actual loss can be isolated by activity, not estimated globally
  • Engage the QS early and share draft substantiation before formal submission to flag gaps while they're still fixable
  • Reference the exact clause and Relevant Matter in every application - vague wording invites vague responses
Commercial manager cost-coding site records on a laptop to support a JCT loss and expense submission

Frequently Asked Questions

What is loss and expense under JCT?

Loss and expense is direct financial loss a contractor incurs when the regular progress of the works is materially affected by a listed Relevant Matter, recoverable under clauses 4.20-4.23 of the JCT Standard Building Contract, provided the contractor applies in writing and substantiates the amount.

What are Relevant Matters under JCT clause 4.21?

Relevant Matters are the closed list of qualifying grounds for a loss and expense claim, including employer instructions, late information, opening up work found to comply, deferment of possession, antiquities, and disruption caused by the employer's other contractors.

What is the difference between a Relevant Matter and a Relevant Event?

A Relevant Event (clause 2.29) justifies an extension of time and protects the contractor from liquidated damages. A Relevant Matter (clause 4.21) justifies a claim for loss and expense - financial compensation. Some circumstances qualify as both, but they're assessed under separate clauses.

How quickly must a contractor submit a loss and expense application?

As soon as it has become, or should reasonably have become, apparent that regular progress is being or is likely to be materially affected. Courts treat this timing requirement as a condition precedent, so a late application can extinguish the entitlement even if the underlying loss is genuine.

Can a contractor get an extension of time but not loss and expense?

Yes. EOT and loss and expense are assessed under separate clauses with separate notice requirements. A contractor can win extra time under clause 2.29 while being time-barred from money under clause 4.20 if it failed to submit the separate loss and expense application.

Why do loss and expense claims get rejected?

The most common reasons are late notice, submitting a global claim without linking specific events to specific costs, weak or missing contemporary records, and double-counting costs already recovered through variations or other contract sum adjustments.

What evidence is needed to support a loss and expense claim?

Programme and progress records, site diaries, correspondence establishing the Relevant Matter and its date, cost records such as invoices and timesheets tied to the affected period, and a clear causal chain linking each cost claimed to a specific Relevant Matter.

Final Thoughts

A loss and expense claim JCT process rewards discipline more than drama. The Relevant Matters are fixed, the notice requirements are strict, and the ascertainment exercise is fundamentally a factual one - what was actually lost, evidenced by real records, not a formula applied after the fact.

Contractors who treat notice and substantiation as live, ongoing site disciplines - rather than a paperwork exercise bolted on after the disruption has passed - consistently recover more, faster, and with far less friction than those who wait until the final account to make their case.

Whether you're preparing the application or assessing one, the same test applies throughout: is there a genuine Relevant Matter, was it notified in time, and can the loss claimed be traced, event by event, back to that cause?

Want the full picture? Want to go deeper on JCT claims and disputes?

Read our companion guides on NEC4 vs JCT contract comparisons and Construction Adjudication Explained for the wider picture on how claims escalate when they can't be resolved by agreement.