Proportionality Challenges in Detailed Assessment

3 days ago
3 min read

Proportionality is one of the most effective tools available to paying parties when challenging a bill of costs. Even where individual items appear reasonable, the court may reduce the total if the overall figure is disproportionate to the value, complexity, and importance of the claim. Structured proportionality arguments are therefore central to detailed assessment and form a key part of modern paying party strategy.

Details of our paying party work can be found here.

The Proportionality Test

Under CPR 44.3(5), costs must bear a reasonable relationship to:

the sums in issue
the value of non-monetary relief
the complexity of the litigation
the conduct of the parties
any wider factors such as reputation or public importance

This creates a global assessment of the bill rather than a purely line-by-line exercise.

Global Reductions at Detailed Assessment

Where the total costs figure is disproportionate, the court may apply an overall reduction even if individual items were reasonably incurred. This is why paying parties assess:

the level of partner involvement
the scale of expert evidence
the number of fee earners
duplication of work
whether the case justified the resources deployed

These issues frequently overlap with Guideline Hourly Rates challenges and delegation arguments.

Recent Authority on Proportionality

Recent decisions confirm the court’s willingness to apply stand-back proportionality reductions even after a detailed line-by-line assessment. In XX v Young (SCCO, 2025), a bill reduced from £517,000 to £339,000 on individual items was still held disproportionate, leading to a further global reduction. This reinforces that passing a reasonableness test does not protect a bill from a subsequent proportionality cut.

In Coram v DR Dunthorn & Son Ltd [2024] EWHC 672 (KB), leading counsel’s fees were disallowed as disproportionate when measured against the value and complexity of the claim. The decision highlights the vulnerability of high-level representation on the standard basis where the litigation does not justify the cost.

Budgeting decisions are also increasingly driven by proportionality. In Worcester v Hopley [2024] EWHC 2181 (KB), the court reduced a costs budget by more than half, criticising the parties’ failure to engage with proportionality at the case management stage. This confirms that proportionality is now a front-line filter in costs management rather than an issue reserved for detailed assessment.

These authorities demonstrate that paying parties should deploy proportionality arguments both at budgeting and at assessment as part of a structured costs defence.

Proportionality and Delegation

Poor delegation is frequently central to disproportionate costs. Routine tasks carried out by senior fee earners, multiple attendances by different grades, and unnecessary conferences can all lead to reductions when viewed against the value and complexity of the claim.

Interaction with Fixed Costs and Scope Arguments

In cases where fixed recoverable costs may apply, proportionality arguments often arise alongside disputes about whether the claim falls within the fixed regime. Paying parties therefore analyse both scope and proportionality when preparing Points of Dispute and advancing fixed costs arguments.

Conduct and Proportionality

Conduct allegations are sometimes used by receiving parties to justify higher expenditure. Paying parties must test whether the conduct relied upon genuinely caused additional work and whether it meets the threshold for increased recovery, in line with recoverability and conduct principles

Evidence-Based Proportionality Challenges

Successful proportionality arguments rely on:

comparing costs to the value of the claim
identifying routine work billed at senior rates
demonstrating duplication or inefficiency
analysing the procedural history against the resources claimed

This moves the argument from assertion to evidence and strengthens negotiation before a hearing.

Commercial Impact for Paying Parties

Proportionality challenges can lead to substantial reductions, particularly in lower value or routine claims where the level of work claimed exceeds what the litigation required. Early analysis improves settlement outcomes and reduces exposure before detailed assessment.

This is particularly relevant for local authorities, insurers, and defendant litigation teams managing high volumes of costs disputes.