Costs Litigation Blog

Author: Robert Oldham, 12KBW

The High Court’s decision in Mazur & Anor v Charles Russell Speechlys LLP [2025] EWHC 2341 (KB) is a far-reaching regulatory decision with significant costs implications. This will open up new battles over recoverability, shake up staffing models, and create exposure to challenge.

The Decision

The central issue before Sheldon J was whether an unauthorised employee could lawfully conduct litigation under the supervision of an authorised solicitor.

In the litigation subject to appeal, an unauthorised employee of Goldsmith Bowers (who had been instructed by Charles Russell Speechlys in a debt recovery claim) had signed pleadings despite lacking a practising certificate.

The defendants obtained a stay; CRS applied to lift it and were awarded costs of £10,653 at first instance. This decision was then appealed to the High Court.

On appeal, the High Court held:

• The unauthorised employee was not entitled to conduct litigation, even with supervision. Section 21(3) of the Legal Services Act 2007 brings unauthorised employees within regulatory reach, but it does not confer litigation rights.

•  Conduct of litigation is a reserved activity and cannot be delegated to unauthorised persons. The line between support (which is permitted) and conduct (which is prohibited) is one of fact and degree.

• On costs, the first instance order was overturned and fixed costs of £333 and the court fee of £303 were awarded. The application was held to fall within the intermediate track fixed costs regime.

Costs Implications

Escalating Time Costs and Staffing Pressures

The most immediate effect is upward pressure on time costs. Work long delegated to paralegals or litigation executives risks being recategorized as ‘conducting litigation’ and therefore must remain in the hands of authorised solicitors. This affects not only high-volume work subject to fixed costs regimes, but also complex, higher-value litigation where teams often rely on junior staff to manage initial pleadings and applications. Firms will need to revisit file structures, supervision arrangements, and how work is recorded.

Cost Recovery

This case also opens up a hitherto rarely seen line of attack for paying parties: expect challenges at detailed assessment on the basis that parts of a bill were carried out by unauthorised staff and should be disallowed. However, this may prove to be a double-edged sword – firms now have a good reason to push more work to higher-grade solicitors to insulate against this accusation, thereby driving costs higher.

For solicitors in higher-value litigation, where detailed assessment is already a fine-grained exercise, Mazur will increase arguments about delegation, billing narratives, and the exercise of professional judgment. Costs judges may probe not only who performed the work, but whether an authorised solicitor demonstrably retained control.

Future Disputes

Expect a proliferation of costs skirmishes. Paying parties may argue that swathes of time are irrecoverable; receiving parties may counter by insisting that only qualified staff could safely carry out the work post-Mazur. The potential for satellite litigation is clear, especially following detailed assessment.

Fixed Costs — a Reminder

Finally, Sheldon J’s decision to restrict costs to the fixed regime of the intermediate track reminds us that the courts will be reluctant to step outside prescribed costs regimes, however complex the underlying issue. Exceptional circumstances must truly be exceptional.

Some Practical Considerations

As the dust settles from Mazur, practitioners may wish to consider:

• Auditing staffing models and identifying tasks that cross the line into reserved activities.
• Ensuring that an authorised solicitor is the ‘responsible litigator’ on each case and that this is evidenced.
• Revising billing narratives so that delegation and supervision are transparent and defensible.
• Updating retainers and estimates to reflect possible increases in qualified fee-earner involvement.

Conclusion

Mazur will have a huge impact on the economics of litigation across the board. For solicitors, the challenge is twofold: ensuring compliance with the Legal Services Act while preserving costs recoverability and the economic viability of higher-volume litigation.

To note. The SRA issued a statement to the effect that:

• Mazur does not change the position in law. Only regulated individuals can conduct litigation under the  Legal Services Act 2007.
• There is a distinction between conducting litigation and supporting litigation, but the boundary between the two activities will depend on the facts. 
• The onus is on firms to satisfy themselves that they are complying with the LSA, and they should record the decision-making process on this.