Roger Mallalieu QC has been a member of 4 New Square since 2008 and took silk in 2020. He is ranked as a leading practitioner in the field of costs law and has been involved in many of the leading cases in the area.

Recognised by the directories as a “guru on costs” with a “formidable reputation”, he has been described in the directories as “absolutely smashing” and “simply the best when it comes to costs law.” “He really is something else. He knows the area so incredibly well but he’s never overbearing with that knowledge. His approach is really helpful and his strength is when he’s on his feet: he’s a fantastic advocate.” He “wins considerable market acclaim due to his broad knowledge base and restrained yet steely manner” with a particular comment made of his ability to “bringing clarity and depth to the case” and his ability then to “integrate that into a team approach to get the best result”. He regularly appears in the Court of Appeal on important costs cases and has been instructed in some of the few costs cases to have been heard in the Supreme Court, including successfully representing the Appellant in the Supreme Court case in Ho v Adelekun.

In addition, Roger also has a well-established practice in the fields of professional negligence and in relation to disciplinary matters involving solicitors, particular relating to costs and funding issues.

He is a specialist in all aspects of the Civil Procedure Rules, including Part 36, and has appeared in a number of the leading appellate cases in this area. Roger also undertakes some general commercial contract law work.

Roger is particularly attracted to complex technical issues and prides himself on his ability to work with his professional and lay clients to develop and then pursue a comprehensive strategy to deploy or respond to such issues at all levels.

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Areas of Expertise



Roger has extensive experience in all areas of costs law.

He is listed as a leading silk in the field in both the Legal 500 and Chambers & Partners.

“Roger is the one you want advocating for you in court: polished, personable, persuasive and poised.” – Legal 500, 2022

“Immensely likeable, he inspires confidence, works through issues in a down-to-earth way and brings you along on the journey, keeping you involved.” “You turn to him when you have complicated costs issues as he has the no-nonsense approach that you need from a costs silk. He is known in the industry for being an encyclopedia in this area.” “Roger is polished, prepared and has a great manner with clients. Judges listen to him.” Chambers & Partners, 2022

“Has long been considered the best junior in the costs field and now may equally lay claim to the title as QC.” – Legal 500, 2021

“Displays great gravitas when appearing before either a High Court judge or Court of Appeal justice. He leads the way in terms of costs and is great with clients.” “Roger is composed, very logical and someone who has a wonderful way with clients.” – Chambers & Partners, 2021

The best costs advocate of the junior Bar. – Legal 500, 2020

“A leading expert in costs litigation, who provides fantastic practical advice and is not afraid to roll his sleeves up.” “Roger can speak to the man off the street as well as to a Supreme Court judge.” “He thinks of things from all angles, covers all options and always seems to have a secondary argument in his back pocket.” – Chambers & Partners, 2020

“Excellent on his feet, very assured and respected by judges and other barristers.” “He has the ability to get to the key points that we need to focus on in order to win.” – Chambers & Partners, 2019

“Breaks the complex information down into digestible chunks” – Legal 500, 2019

“A persuasive advocate, who is head and shoulders above the competition.” – Legal 500, 2017

‘An Incontrovertible star who enjoys a “formidable reputation” in the field as a “guru on costs.” His written work is highly persuasive and he has the voice of a good friend talking you round. As an advocate, he is formidable and his command of the material is stunning.” “He’s good with clients, immensely likeable and is someone who engenders confidence and trust.”’ – Chambers & Partners, 2016. 

Inter partes costs

Roger’s practice covers the complete range of inter partes costs matters, from representing clients on complex or high value detailed assessments, through technical arguments concerning the validity of retainers, to disputes about insurance premiums and other similar matters. Roger represents clients in such matters at all levels and appears regularly in the appellate courts.

In addition, much of Roger’s work is of an advisory nature, ensuring parties are best prepared to maximise costs recovery or seeking to lay the ground for successful challenges to the principle or quantum of costs.

Roger was involved in some of the leading cases concerning costs capping and budgeting. He also has considerable experience in dealing with security for costs applications.

Roger is regularly instructed to advise on or represent parties in litigation concerning millions of pounds in costs and is experienced in dealing with group litigation claims.

Roger regularly acts for both defendants and claimants and has been instructed in some of the most high profile costs litigation in recent years.

He has represented a wide range of clients from high street PLCs to presidents of African countries, through to music celebrities and celebrity footballers in a wide range of interesting and complex cases.

Solicitor – client costs

Roger is regularly instructed to represent solicitors seeking to recover costs from their clients and by clients seeking to resist paying such costs, in complex and high value cases. He has extensive experience in all aspects of solicitor-client matters and has a particular expert knowledge of the intricacies of the Solicitors Act 1974 in this regard.

He is also frequently instructed in cases where there is an overlap between such issues and a professional negligence claim by the client and/or professional conduct proceedings against the solicitor.

Drafting and advisory work

A significant part of Roger’s practice concerns the provision of drafting and advisory work, whether on an individual or generic basis. Roger has drafted many fee-related agreements, including conditional and collective conditional fee agreements, costs sharing agreements and similar matters, for a range of firms including large city firms and has substantial experience of advising such firms on novel and complex fee arrangements and on how to maximise solicitor-client and inter partes costs recovery.

Other areas

Roger has experience in a range of other costs related areas, including costs of arbitrations, costs of administrations and receiverships and costs disputes between solicitors and counsel, including references to the Joint Tribunal. He has acted in a number of complex cases concerning applications for third party costs orders.

Examples of experience

Recent cases include:

  • Sibthorpe & Morris v London Borough of Southwark (Law Society intervening) (Court of Appeal, December 2010). Roger acted for the Defendant in this second appeal to the Court of Appeal in relation to the question of the extent to which champerty and maintenance continue to restrict the scope of a solicitor’s retainer and the legality of a solicitor indemnifying a client against an adverse costs liability,. Judgment is awaited.
  • In the matter of Super Aguri F1 Ltd [2010] (full reference awaited). Roger acted for the successful joint Adminstrators in an extremely contentious application for their remuneration to be fixed and  thereafter in their successful claim for the recovery of the administrators own costs, in addition to ‘legal costs’, of that application.
  • Forde v Birmingham City Council [2009] 1 WLR 2732, the leading case concerning the validity of retrospective conditional fee agreements.
  • Tankard v John Fredericks Plastics & others [2009] 1 WLR 1731 (CA), the Court of Appeal test cases concerning conditional fee agreements and the Accident Line Protect insurance scheme.
  • Nizami v Butt [2006] EWHC 159 (QB) concerning fixed costs in road traffic cases.

In addition, Roger has been instructed in a number of high-profile Court of Appeal cases, including a second appeal concerning the ability of solicitors to ‘insure’ their clients and a second appeal concerning the interaction of CPR Part 36 with the fixed costs rules.

Roger is regularly asked to write articles on or to lecture on costs and has written articles for the Personal Injury Law Journal, the Solicitors Journal, the Butterworths Civil Costs newsletter and the Practical Law Company amongst others.

Professional Liability


Roger has extensive experience in the field of professional negligence, in particular clinical negligence and complex personal injury cases. He has particular expertise in the field of catastrophic spinal injury cases and regularly acts for severely injured clients seeking seven figure sums in compensation. His experience in this field, combined with his expert costs expertise and knowledge of the scope of solicitors’ duties, the Solicitors’ Code of Conduct and the Solicitors’ Act 1974 and considerable experience in cross-examining solicitors and clients place him in an excellent position to deal with professional liability matters relating to lawyers and in particular in relation to professional liability matters arising out of clinical negligence and personal injury claims and Roger has expanded his practice in this regard since moving to 4 New Square.



During his earlier period of practice, Roger had a very extensive and successful practice representing doctors before the General Medical Council. Since that time, Roger has combined that expertise with his expertise in other areas to solicitors’ disciplinary work.

In particular, Roger is instructed, whether to advise or represent, in relation to cases relating to solicitors’ relationships with their clients or with third parties, for example in relation to fee sharing arrangements or similar matters.

Qualifications & Memberships

Roger is a member of the Professional Negligence Lawyers Association and the Commercial Bar Association.

LLB (1st Class) University of Newcastle upon Tyne 1997. Diplock Scholar, Middle Temple.


VAT registration number: 744299111