Simon Teasdale

Simon’s practice focuses heavily on costs litigation, with a particular specialism in solicitor-client disputes. Simon is ranked as a Leading Junior in costs law by Chambers & Partners and the Legal 500 and is a ‘go to’ junior in this area.

Recently, Simon has appeared in three major appeals before the Court of Appeal in relation to costs:

1. Diag Human SE & Stava v Volterra Fietta [2023] EWCA Civ 1107;
2. Thomson Snell & Passmore v Kenig [2024] EWCA Civ 15;
3. Signature Litigation LLP v Ivanishvili [2024] EWCA Civ 901.

“He is five steps ahead of everyone else in the room. Simon is charming, strategic and really personable.” – Chambers & Partners

“Simon is leagues ahead of other juniors, his written advocacy is what one would expect from silks.” – Legal 500

“Simon’s written and oral submissions are very polished. An exceptionally talented advocate with razor sharp insight leading straight to the core of the issue. He could be a future star.” – Legal 500

Simon’s recent cases and instructions in this area include:

• Acting (led by Benjamin Williams KC) for c.1.8 million claimants in the ‘Dieselgate’ NOx Emissions Litigation, believed to be the largest group action ever brought in this jurisdiction. The proceedings have encompassed applications for information about the funding of the claimants and their lawyers, and the largest cost budgeting exercise ever performed by the English courts (Pan NOx Emissions Litigations, Re [2024] EWHC 1728 (KB)).
• Acting on behalf of Woodsford Group Limited in both the Stagecoach (Stakeholder Entitlements Hearing) [2025] CAT 72 and CSAO approval application in Mark McLaren Class Representative Limited v MOL (Europe Africa) Ltd [2026] CAT 6 .
• Acting (led by Nicholas Bacon KC) for the boutique arbitration firm Volterra Fietta in the important appeal of Diag Human SE & Stava v Volterra Fietta [2023] EWCA Civ 1107, regarding the enforceability of Volterra Fietta’s retainer for work done in relation to a multi-billion-dollar BIT Arbitration.
• Acting as sole counsel for more than 50 individual claimants in relation to the assessment of costs incurred in the ongoing MTVIL ‘phone hacking’ litigation against News Group Newspapers Ltd.
• Acting unled for the Quin Emmanuel claimant cohort in the multi-billion dollar action against Glencore plc (Aabar Holdings S.À.R.L & Others v Glencore Plc).
• Acting (led by Roger Mallalieu KC for the successful respondent in Signature Litigation LLP v Ivanishvili [2024] EWCA Civ 901, which is now the leading authority on the requirements of a statute bill and the ability to deliver same in cases conducted under a conditional fee agreement.
• Acting (led by Roger Mallalieu KC) for the successful respondent in Thomson Snell & Passmore v Kenig [2024] EWCA Civ 15, which has revolutionised the rights of assessment available to beneficiaries under trusts and wills.
• Acting (led by Daniel Saoul KC) for D14 in the multi-million-dollar consolidated assessment proceedings arising out of The Public Institution for Social Security v Al Rajaan & Others in the SCCO.
• Acting for Harbour Fund IV LP (led by Roger Mallalieu KC), the commercial funder for the Claimant in the multi-billion-pound Suppipat & Ors v Siam Commercial Bank Public Company Ltd & Ors (one of the Lawyer’s Top 20 cases of 2022) including the defence of an application against Harbour Fund IV for security against the Defendants’ combined projected costs to trial of more than £67m.
• Acting unled for Mishcon de Reya in Borderedge Limited v Mishcon de Reya LLP, an assessment of the firm’s costs incurred while acting for Borderedge Ltd in the notorious multi-jurisdictional enforcement proceedings which followed the Akhmedov/Akhmedova divorce proceedings.
• Advising in relation to the availability of Non-Party Costs Orders against both parties and their lawyers, particularly in the context of costs proceedings themselves.
• Acting for Charlton Athletic Football Club in SCCO proceedings relating to the costs claimed by its former club solicitor, IPS Law.
• Being led by Roger Mallalieu KC on behalf an international client bringing multi-million-pound assessment proceedings against a city firm, including a challenge to the enforceability of the firm’s CFA.
• Advising in relation to the assessment and recovery of costs in the Supreme Court.
• Being led by Nicholas Bacon KC in a claim brought in the Commercial Court by a major city firm against former clients. Simon acted for two defendant trustees that were alleged to be liable for unpaid fees and interest totalling more than £6m. The litigation involved issues of wrongful termination of retainer, quantum, and the holding of hearings in private.
• Appearing unled, against Nicholas Bacon KC, for the local authority in Cameron v Leicester City Council (2021) – an important appeal regarding the operation of the Part 45 fixed costs regime.
• Being led by Nicholas Bacon KC for the successful solicitors in Mr H TV Limited v Archerfield Partners LLP, detailed assessment proceedings brought by a former client, including a three-day preliminary issue trial on the question of whether £3.6m of costs had been ‘approved’ for the purposes of CPR 46.9(3)(a) and (b).
• Being led by Robert Marven KC in an application for security for costs within a Solicitor Act assessment (and the determination of the important question of whether such an applications can be made in such proceedings).
• Advising in relation to solicitors’ liens, delivery up of clients’ files, charging orders pursuant to section 73 of the Solicitors Act 1974, and disclosure obligations in detailed assessments.
• Acting as sole counsel (and led) for major city firms seeking to bring claims against former clients for the payment of fees. Simon has substantial experience in advising on the status of statute bills, the pleading of claims for recovery of fees, and acting in litigation between solicitors and their former clients.
• Successfully defending a Part 35 Expert against an application for the third-party costs order.
• Acting on behalf of a barrister who had been made subject to a wasted costs order within the bankruptcy proceedings of a former client.