Arnold Ayoo
“Arnold is a star in the making at the Bar” with “… gravitas in his advocacy”. "He leaves no stone unturned".
Legal 500 and Chambers UK
- Call
- 2014
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- +44 (0)20 7583 9020
- Email:
- aayoo@hendersonchambers.co.uk
Arnold practices in heavy commercial litigation/arbitration and specialises in cases with an insolvency crossover. He has expertise in group litigation and civil fraud and is ranked by the directories as a leader in commercial dispute resolution, company law and insolvency. He is Standing Counsel to the Competition and Markets Authority, representing the government department in its major litigation.
Arnold is comfortable at every level of the Court system. In the High Court, he has recently acted (unled) in multiple civil fraud cases: securing a £2m worldwide freezing order (Argyle Rose Ltd v Naaz [2024] 3 WLUK 835); defending a $14m unlawful means conspiracy claim (Gupta v Shah [2024] EWHC 1189 (Ch) and defeating a contempt application (Landmark Space Limited [2024] EWHC 987 (KB). In the Court of Appeal, he appeared (unled) in a significant insolvency case concerning the CIGA 2020 (Doran & Anor v County Rentals Ltd [2022] EWCA Civ 137) and he featured in a landmark Supreme Court case concerning contract and unjust enrichment (Barton v Morris [2023] UKSC 3).
In 2025 Arnold is instructed as sole counsel on four significant Commercial Court actions (a $60m conspiracy claim brought by an African oil company; a £30m unlawful means conspiracy claim; a £20m claim to enforce an expert SPA determination; and a £3m commission dispute brought by an investment bank). He is also led on two group actions: acting for a German manufacturer in the Dieselgate litigation and for the claimants in a £400m secret commission claim.
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Expertise
Civil Fraud
Arnold has extensive experience handling civil fraud cases, representing clients in both domestic and international matters. He is well-versed in advising on and securing critical interim remedies, such as domestic and worldwide freezing injunctions, including in support of foreign proceedings.
His expertise includes cases involving misrepresentation, breach of trust, breach of fiduciary duty, conspiracy, knowing receipt, and unjust enrichment. He is adept at advising on all key fraud remedies, both personal and proprietary.
Representative cases
grid list-
Gupta v Shah [2024] EWHC 1189 (Ch)
Arnold continues to act on behalf of the fourth defendant in a $14m unlawful means conspiracy and fraudulent breach of trust claim. In May 2024, he successfully resisted the claimant’s application to (a) debar his client from continuing to defending the proceedings and (b) obtain a summary award of $14m. Arnold will appear (unled) at trial.
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Larsson v Revolut Ltd [2024] EWHC 1287 (Ch)
Significant case concerning the role and liability of receiving banks where the customer of a sending/paying bank has been the victim of an APP fraud. Arnold acted for the Claimant, who had been defrauded of a six figure sum in a fictitious investment scam concerning Elon Musk’s ‘starlink’ business.
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Landmark Space Limited [2024] EWHC 987 (KB)
Arnold successfully acted (unled) for the defendant before Griffiths J, against a leading silk. The claimant was applying for permission to make a contempt application against D, in order to commit her to prison, on the grounds that D had knowingly made a false statement in an affidavit during massive breach of confidence proceedings which followed a data breach.
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Argyle Rose Ltd v Naaz [2023] EWHC 2403 (Ch); [2023] 3 WLUK 835
Civil fraud claim arising out of diversion of business profits by a business associate operating a secret shadow business. Arnold acted for the successful applicants in obtaining a WFO (£2m), proprietary injunctions (covering the proceeds from a diversion of business), permission to serve out of the jurisdiction and alternative service by WhatsApp.
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Manetta v De Filippo [2020] EWHC 3460 (QB)
Acted as sole counsel for the applicant who applied to adapt an Italian freezing order into an English freezing order for the purpose of its enforcement in this jurisdiction. A novel application brought for an ‘adaptation order’ under CPR 74.11A and Article 53 of the Recast Brussels Regulation.
Commercial and Company
Arnold has extensive experience in heavy commercial litigation, often appearing in cases with an international element. He is ranked as a leader in this field by both Chambers UK and Legal 500.
His practice covers the spectrum of claims arising from commercial business arrangements, especially where fraud is at issue. Ranked as a leading junior in company law (Legal 500 2025), he also acts in partnership and shareholder disputes, including unfair prejudice petitions and derivative actions.
Representative cases
grid list-
Barton v Gwyn-Jones [2023] UKSC 3
Led by Brad Pomfret, acting for the respondent, in a generationally important appeal on contract/unjust enrichment before the Supreme Court. It concerned the contractual allocation of risk, implied terms, the sanctity of contracts principle, and the limits of unjust enrichment where a contract subsists.
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B v K [2025] (Commercial Court)
Arnold continues to act (unled) on a £30m enforcement action concerning a foreign judgment, allied with interim £23m freezing orders under s.25 CJJA in support of the foreign proceedings.
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Re DTSN Ltd [2025] (Insolvency & Companies Court)
Multimillion pound unfair prejudice petition concerning two Michelin starred restaurants. Arnold is instructed through to trial.
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Alphier Capital v Blyvoor Gold [2024] EWHC 2649 (ChD) and ongoing
$2.6 million debt claim arising from the procurement of finance for a South African gold mine. Arnold leads Kate Gardiner and will appear at trial in 2025.
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Jewkes v Watson [2023] EWHC 2993 (Ch)
Arnold is instructed by the claimant in a $700,000 debt claim relating to unpaid instalments under a deed of assignment, defended on grounds of undue influence. In November 2023, AA appeared in the ChD and was successful in striking out three (out of four) strands of the defence – non est factum, duress and frustration. He will act in a four day trial in 2025.
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Natwest v Otero [2023] (Chancery Division, unrep)
Arnold acted (unled) for the bank, which alleged that D unlawfully retained thousands of customer documents after her dismissal and used them as leverage to try and obtain a post-dismissal ‘settlement’. D proceeded to contact the affected customers, recite their confidential information to them and direct them to complain to the bank – as well as informing media outlets. The bank sued for breach of confidence; AA obtained an injunction before Richards J in the ChD
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Re SPA [2022] (Commercial Court)
Acting (unled) for 8 claimants against 7 defendants in a £17m claim for deferred consideration following the expert determination of elements of an £90m SPA.
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AC v BG: [2021] (Commercial Court)
Currently instructed as sole counsel for the Claimant in a £3m commission claim. C is the assignee of a debt owing to an investment bank, who claims to have brokered a $50m investment in a South African gold mining company and seeks commission, as per a contract.
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AR & Ors v Loizou [2022] (Chancery Division)
Represented a lateral testing business, alleging that D fraudulently hacked their websites/email accounts and manipulated software to divert online payments to his own bank account. Cs claimed a fraudulent breach of confidence, passing off, various economic torts and damages (est over £1m). Arnold successfully obtained interim injunctions (before Johnson J and James Pickering QC as a Deputy HCJ) to return the websites to Cs control and prevent further breaches of confidence.
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Points of View Ltd v Erre DB Group SA [2021] 2 WLUK 70
Acted (unled) and obtained a £400,000 judgment for the claimant against a Swiss developer in a cross-border construction dispute, arising from the construction of the flagship Flannels store on Oxford Street.
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Capital Funding One Ltd v Esqulant [2020] EWHC 981 (QB); [2020] 4 WLUK 253
Represented (as sole counsel) a short term bridging lender at trial through to appeal in its claim to enforce its security following a default on a £300,000 loan. The appeal decision had significant ramifications for both CPR 34.2 (witness summonses) and CPR 32.10 (evidence at trial) – and is included in the White Book Commentary to the latter.
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Ziheng Zu v Han Ning Lim [2020] (County Court, HHJ Roberts)
Acted for the successful defendant in a £200,000 shareholder dispute. D brought a security for costs application on the basis that the claimant was resident in China. It required proving that China was not bound by any relevant multilateral enforcement treaty and would not enforce an English costs awards.
Insolvency
Arnold is recognised by the Legal 500 as a Leading Junior in this field (Tier 2). He has a breath of experience in insolvency and restructuring proceedings, and is at home in complex, contested disputes. His practice covers contentious and non-contentious, personal and corporate insolvency and restructuring – including administrations, voluntary arrangements, liquidations, bankruptcy and claims under the Insolvency Act 1986, especially wrongful and fraudulent trading, misfeasance, preferences, transactions at an undervalue and transactions to defraud creditors.
He has written for Lexis Nexis on insolvency and restructuring law and has contributed LexisPSL case updates on cases of importance in which he has been involved. In late 2021, he appeared in a landmark appeal in the High Court concerning the interpretation of the coronavirus test under the Corporate Insolvency and Governance Act 2020.
Arnold also advises on the non-contentious aspects of restructuring which have the capacity to develop into disputes. For example, much of his 2020 post-covid practice was advising multi-national retailers on CVAs which restructured rent obligations following the demise of the high street.
Representative cases
grid list-
Re Daman National Limited [2025] (Insolvency & Companies Court)
Arnold represented (and continues to represent) the Joint Liquidators in various applications in a complex liquidation in relation to a company suspected of fraudulent activity, including: (i) an application pursuant to s.236 Insolvency Act 1986 for an order that the respondents provide information in relation to the company (ii) an allied application for an arrest warrant against a delinquent s.236 respondent, resulting in his detention at Gawtick Airport and (iii) an application for a validation order, dismissed by ICC Judge Prentis on the ground that the continued trade would be illegal.
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Scandico v Tronic [2025] (Insolvency & Companies Court)
Validation order application and joint liquidators’ cross application for a declaration that six figure payments are void, pursuant to s.127 Insolvency Act 1986. Arnold is continuing to represent the joint liquidators.
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Re Company A [2025] (Insolvency & Companies Court)
Advising and acting for the joint liquidators dispute concerning a series of seven figure payments made by the Company amounting to 1) a transaction at an undervalue; (2) s.423 claim (transaction defrauding creditors) and (3) unjust enrichment.
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Re Company S [2025] (Insolvency & Companies Court)
Advising and acting for joint administrators respect of applications under sections 238, 239 and s.423 of the Insolvency Act 1986 concerning allegations that directors had misappropriated £500,000.
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O v D [2022] (Commercial Court)
Acting (unled) for the liquidator of a Bermudan information and communications technology company, together with 6 other claimants, in a €20m claim to recover sums due following the sale of an arm of its business.
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Reputation Exchange PLC v Paneleven [2022] EWHC 3627 (Ch)
Appeared for the respondent in an injunction to prevent the presentation of a winding up petition. The judgment concerned the proper standard of proof in substantial dispute allegations, cross-claims and counterclaims.
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LW v C & others [2022] (ChD)
Currently acting (unled) in a £4m claim under s.423 of the Insolvency Act 1986 (intention to defraud creditors). The claimant avers that the third defendant, whom Arnold represents, conspired with D1/D2 to sell commercial developments at massive undervalues, depriving the claimant of the true value of its security.
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Wolf Rock (Cornwall) Limited v Langhelle [2021] B.C.C. 67
Successfully acted (unled) for the petitioner at trial and appeal. At trial, Arnold obtained a compulsory winding up order and resisted attempts to bring cross claims of £7m. At appeal, HHJ Matthews decided key questions on insolvency procedure and the jurisdiction to make a winding up order where the sum is ‘unliquidated’ or concerns damages. It appears in Sealy & Milman 24th Ed (2021) in the commentary to both IR 7.16 and s.124(1) Insolvency Act 1986.
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Doran v County Rentals Limited [2021] EWHC 3478 (Ch)
Appeared (unled) for the appellant petitioner in a landmark appeal concerning the interaction between insolvency and coronavirus. It concerned whether a company can rely on coronavirus to defeat a winding up petition in respect of sums which fell due pre-pandemic but not formally demanded until after the pandemic. The judgment examines the circumstances when an inference of insolvency can be drawn from the fact of non-payment.
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Charlton v Funding Circle [2019] EWHC 2701 (Ch)
Acted for the Trustee in Bankruptcy in an appeal before the Vice Chancellor following an application to annul a bankruptcy. The VC decided the proper interpretation of s.265(2) of the 1986 Act (in respect of domicile, residence and carrying on business).
Consumer
Arnold has an interest in abusive market practices. He is Standing Counsel to the Competition and Markets Authority (CMA), the UK’s primary competition and consumer authority, which is an independent non-ministerial government department with responsibility for carrying out investigations into market practices and enforcing competition and consumer law.
Arnold advises the CMA on its functions under the Digital Markets, Competition and Consumers Act 2024, which establishes a new administrative enforcement model of consumer protection, and represents it in the Courts.
Arnold also acts in mass private actions brought by and against consumers, such as the mammoth Dieselgate litigation [2024] EWHC 695 (KB), in which Arnold is instructed as first junior counsel to a German manufacturer. It includes consumer allegations of fraudulent misrepresentation, breach of contract, breach of statutory duty (breach of EU emissions regulations), breach of regulation 5 CPUTR 2008 (including redress under Part 4A) and a competition claim (breach of Article 101 of the TFEU and/or Chapter 1 of the CA).
Commercial Arbitration
Arnold’s international arbitration work has encompassed contractual disputes involving interpretation, termination and breach; fraud claims; allegations of repudiatory breach and estoppel; claims for specific performance and other mandatory remedies; quantification of loss requiring complex modelling; admissibility of documents and disclosure in the arbitral context; proof and application of foreign law by expert evidence; and assistance with and presentation of other expert evidence.
Representative cases
grid list-
MM v HZ [2025] (ICC – London Seat)
Acted in a $2m ICC arbitration concerning a multinational franchise agreement – breach of contract.
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AZ v UL [2024] (ICC - London Seat)
Currently acting in ICC arbitration between an Eastern European government owned oil company (for whom Arnold acted, as sole counsel) and its pipeline supplier in a breach of contract, unjust enrichment, and breach of trust claim.
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SO v IP [2020] (ICC - London Seat)
An $6m ICC arbitration between a government appointed oil exploration company (for whom Arnold acted, as sole counsel) and its production sharing partner. The breach of contract case involved the interpretation of interlinking production sharing, joint operating, and farmout agreements between an African State, the oil exploration company and its relevant partners.
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Corekci v Cramer [2018] (Football Association Rule K/ Commercial Court)
Successfully acted for a football agent in a FA Rule K arbitration, in respect of agency fees, against a top-flight Turkish footballer. The unsuccessful player then applied to the Commercial Court under s.67/68 Arbitration Act 1996 to set aside the arbitral award, in proceedings heard before Moulder J and Knowles J.
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Thornley v Hull KR [2017] (RFL Independent Tribunal)
Represented an RFL player against his former club before an arbitral tribunal after a disputed transfer from Hull KR to Catalan Dragons.
Group Actions
Arnold readily accepts instructions in large group litigation cases. He has experience of complex and high value commercial group actions.
Representative cases
grid list-
Re Energy Tarrifs / Secret Commissions [2021]
Currently advising 3000 business customers on ‘secret commission’ claims against energy companies arising out of the non-disclosure of payments to energy brokers. Should it proceed, the value of claims would top £90m.
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Terrcorp Limited v Mistry & ors (2020) EWHC 2623 (Ch)
Acted in a claim brought against 174 defendants by land-owning companies who claimed payments under various covenants after the sale of green field sites to the defendant buyers. Arnold advised and acted for a category of representative defendants prior to trial.
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Peel Land & Property (Ports) Ltd v Nawaz & ors [2017-18]
Acting for a group of sub leaseholders and lenders with interests in 75 apartments seeking relief from forfeiture further to the forfeiture of an intermediate lease. Total value of client property at stake in excess of £3m.
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AB v CD (2018)
Advising a group of high-profile cricket, rugby, football and television personalities in a £300,000 claim for professional negligence against former solicitors who had represented them in a dispute concerning tax avoidance schemes linked to the film industry.
What the directories say
"He is very easy to work with and a fully integrated member of the team."
Chambers UK 2025
"Arnold is a middle junior who has real potential."
Chambers UK 2025
"It has been easy and rewarding to work in a team with him."
Chambers UK 2025
"He has excellent communication skills."
Chambers UK 2025
"His approach is assertive and commercial."
Chambers UK 2025
News and articles
Arnold Ayoo appointed by the Competition & Markets...
Arnold Ayoo to speak and lead workshop at Chancery...
Arnold Ayoo appointed to the COMBAR Equality and...
Alerter by Arnold Ayoo & Kate Gardiner - High...
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Legal 500 2025 Guide – Top Tier Rankings for...
Instructing Arnold Ayoo
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BA Law (Jurisprudence), University of Oxford, Christ Church
BPTC, BPP (Very Competent)
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For more information about the way barristers at Henderson Chambers work, including our fee transparency statement and our complaints process, please click here.
Bar Council Number: 62921
VAT Registration Number: 208315041
Legal Status: Barrister
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