Mazur v Charles Russell Speechlys LLP: Litigation Costs Risk and Recoverability After February 2026

The appeal in Mazur v Charles Russell Speechlys LLP, listed for hearing on 24 February 2026, is being discussed largely in regulatory and professional terms. What has received far less attention is its potential impact on litigation costs, recoverability, and exposure to challenge, an omission that may prove costly for litigating firms.

From a costs perspective, Mazur is not a niche regulatory dispute. It goes directly to the question of who is lawfully conducting litigation, a question that sits uncomfortably close to the foundations of litigation costs recovery in England and Wales.

Conduct of Litigation and the Hidden Costs Risk

At the heart of Mazur is the boundary between permitted and non-permitted activities under the Legal Services Act 2007. While the appeal itself will be argued before the Court of Appeal, the downstream consequences are likely to be felt most sharply during costs assessment proceedings.

If litigation is found to have been conducted, even partially, by individuals without the requisite authorisation, several uncomfortable costs questions arise:

• Are those costs recoverable at all?

• Do they fall foul of the indemnity principle?

• Are paying parties entitled to argue that work was unlawfully undertaken and therefore irrecoverable?

• Does delegation and supervision preserve recoverability, or merely complicate the position?

These issues are not academic. They are precisely the arguments that surface late, during detailed assessment, when positions harden, evidence is dissected, and paying parties look for structural weaknesses rather than marginal reductions.

Delegation, Supervision, and Costs Scrutiny

One of the most likely consequences of the Mazur appeal, regardless of outcome, is increased scrutiny of fee-earner roles. Paying parties are already more willing to interrogate who did what, at what level, and under whose supervision.

That scrutiny is no longer confined to hourly rates. It increasingly extends to whether particular work should have been undertaken at all, and whether it was undertaken by someone lawfully entitled to do so.

From a costs drafting and negotiation standpoint, this creates exposure in several familiar areas:

• Hourly rate justification, particularly for paralegals and legal executives

• Challenges to time spent on the basis that work was carried out by an inappropriate fee-earner

• Reduction or disallowance of costs said to arise from improper conduct of litigation

This is where many firms expose themselves. Poorly structured narratives, vague supervision descriptions, and generic time entries invite attack.

These issues are already well-established in Court of Protection costs disputes, where the Senior Courts Costs Office routinely scrutinises delegation, supervision, and recoverability.

Why the Mazur Appeal Should Change How Firms Approach Costs Now

Waiting until after February 2026 to react is a mistake. Costs risk is retrospective.

Bills already drafted, and work already undertaken, may be judged by principles clarified later, particularly where the conduct of litigation is called into question. Firms that assume the risk only crystallises after judgment misunderstand how costs disputes develop.

Prudent firms are already:

• Reviewing how litigation roles are described in bills of costs

• Tightening the way supervision is evidenced and explained

• Stress-testing cases for recoverability risk, not merely quantum

• Seeking specialist input early, rather than at the point of dispute

This is not alarmism; it is realism. The greater the uncertainty at the regulatory level, the more aggressively costs will be challenged.

The Strategic Value of Specialist Costs Support

Mazur reinforces a truth many firms still resist: costs is not an administrative afterthought. It is a risk discipline.

Specialist costs professionals are uniquely placed to identify vulnerabilities that litigators often miss, particularly where recoverability may turn not on the amount claimed, but on how litigation activity is characterised, delegated, and supervised. Getting this wrong does not merely reduce recovery; it can undermine it entirely.

As the appeal approaches, firms that treat costs strategically rather than reactively will be better placed to protect recovery, resist challenge, and justify their positions with confidence.

Final Thought

When the Court of Appeal hands down its decision, much of the profession will focus on regulation and rights of audience. Costs lawyers will be dealing with the fallout.

If your files, narratives, and billing structures are not ready for that scrutiny, February 2026 may arrive with greater exposure and reduced recovery than many firms expect.