Six Months After Mazur: Are Your Files Ready for a Costs Challenge?

Six months have passed since the Court of Appeal’s decision in Mazur v Charles Russell Speechlys LLP [2026] EWCA Civ 369 brought welcome reassurance to firms relying on paralegals and other unauthorised fee earners. The practical question now is how clearly their working arrangements – and the records supporting them – stand up to scrutiny when costs are challenged.

The September 2025 High Court decision had distinguished between assisting an authorised solicitor with litigation and conducting litigation under supervision. It held that an unauthorised individual could do the former but not the latter.

The Court of Appeal rejected that distinction. An unauthorised individual may perform litigation tasks for and on behalf of an authorised individual who retains responsibility. It is the authorised individual who is carrying on the conduct of litigation for the purposes of the Legal Services Act 2007.

The revised judgment separately identifies proper management, supervision and control as regulatory requirements. The necessary oversight varies: some work requires prior approval, while routine work may be appropriately supervised through regular meetings and sampling.

From a costs perspective, a fee earner’s lack of individual authorisation should not, by itself, establish that delegated litigation work was unlawful. However, lawful delegation does not guarantee recovery of every item claimed. Reasonableness and, on the standard basis, proportionality remain central to assessment.

Firms should therefore consider how readily their records explain the arrangements in practice. Can the responsible, authorised individual be identified? Is there evidence of appropriate oversight? Do the records explain the work undertaken by each fee earner?

The SRA’s effective supervision guidance, updated in June 2026, expects firms to be able to evidence their supervision arrangements and the risk-based reasons for the approach adopted. Relevant considerations include the fee earner’s experience and the complexity of the work.

Evidence may include file notes, emails, document reviews and records of case discussions. The guidance recognises that recording every informal supervisory exchange is unnecessary, but firms should make their expectations about recording supervision clear.

Our practical recommendation is to consider the quality of time recording alongside those arrangements. An entry explaining the issue reviewed, the advice given and any resulting action is more useful on assessment than a generic reference to “supervision” or “file review”. It helps explain the purpose of the attendance and address potential objections about duplication.

It is also worth distinguishing between records which evidence supervision and time which is properly recoverable from the paying party. Maintaining a supervision record does not, in itself, make the time chargeable to an opponent.

Six months on, Mazur provides a useful opportunity to review whether the file tells a clear and consistent story about responsibility, delegation and the costs claimed.

If you would like assistance reviewing your time recording and supporting supervision records from a costs recovery perspective, or responding to objections to delegated work, please get in touch with the team at Blackstone Legal Costing UK.

Article dated: 06/10/2026

Rebecca Humble 

Costs Lawyer/Founder