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Hendersons - Barristers' Chambers

Thomas Mallon


Thom accepts instructions across the range of Chambers’ practice areas. He focuses on commercial litigation, consumer finance and insurance, property, group litigation, and product liability. He also has a busy health and safety, public, and regulatory practice.

He is regularly instructed in high-value commercial litigation as junior counsel, having recently acted as junior counsel for Qatar Airways in a £1 billion dispute with Airbus S.A.S. He is currently instructed by the claimant in a £140 million dispute relating to the supply of medical equipment, and in a mass equal pay dispute.

Thom appears frequently in his own right in both the High Court and the County Courts. He represents many of the country’s largest financial institutions, appears in business-to-business contractual disputes, in property disputes whether under the Part 8 procedure or the Part 7 procedure, in claims for unfair dismissal and discrimination in the Employment Tribunal, and in claims for personal injury.

He is the winner of both the Oxford International IP Moot, and the Middle Temple Rosamund Smith Moot. After earning a distinction on the GDL he was granted the prestigious Quatercentenary Scholarship by Middle Temple to fund his BPTC studies.

Before qualifying as a barrister Thom completed his undergraduate studies at the University of Oxford, and then worked the New York and Tokyo trading desks of several multinational banks. While in Japan he earned an MA in Economics from the University of Tokyo, and speaks fluent Japanese.


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Thom has experience across a range of high-value commercial matters.

He is currently instructed as junior counsel in a £140 million dispute involving the supply of medical equipment.

He was recently instructed as junior counsel by Qatar Airways in a £1 billion claim against Airbus S.A.S, which settled.

He accepts all commercial instructions.

Consumer Credit, Banking, and Insurance

Thom has extensive consumer credit experience, regularly appearing in misrepresentation, PPI, undisclosed commission, s.140A-D and s.75 Consumer Credit Act 1974 claims.

He also has a busy practice advising on the interpretation of contracts of insurance.

Thom likewise has significant personal experience in the financial sector, having worked as a trader for several years in New York and Tokyo.

Representative cases

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  • F (in administration) v U & others

    Represented the broker as sole counsel in a £600,000 claim arising out of alleged secret commissions, where it was alleged that the broker had procured the lender’s breach of duty so as to be liable for the same damage.

  • H v Allianz

    Advised as sole counsel on the merits of a £100,000 breach of contract claim against an insurer, following a refusal to pay medical costs incurred as a result of catastrophic heart failure suffered abroad.

  • W v SI International Ltd

    Advised as sole counsel on the recoverability of a £60,000 commission fee payable for the sale of a yacht, after the owner sold the yacht privately and declined to pay any commission to the broker. This advice considered both the effect of the contract itself, and potential claims in equity including quantum meruit.

  • A v DG Holdings

    Advised as sole counsel on the availability of a claim under the Third Parties (Rights Against Insurers Act) 2010, following the insolvency of the insured defendant to a high-value personal injury claim


Thom’s practice covers the full range of property-related matters.

He specialises in Real Property disputes, dealing with mortgages and charges, restrictive covenants, adverse possession and boundary disputes, easements, applications for sale, and land registration and conveyancing disputes.

He also regularly appears in both residential and commercial possession claims, and applications for injunctions.

Representative cases

grid list
  • S v H

    Advised as sole junior as to the beneficial interests held in a family home worth £600,000, where there were six siblings who had resided in the property at different times, but where the property was in the sole name of only one sibling. Further, the father had contributed to the purchase and subsequently died in circumstances where it appeared he may have had the intention to create a trust for the siblings. The advice dealt with the possibility of a trust and the consequences of either a failed express trust or a constructive trust under traditional rules of equity, as well as the likelihood of a common intention or implied trust further to Stack v Dowden and Jones v Kernott.

  • Re: an Estate

    Advised as sole junior on the relative priority of a charging order worth £150,000, as against six prior legal charges, in circumstances where the freehold proprietor had died intestate.

    This advice considered inter alia, ss. 15, 17, 20(1) and20(5) of the Limitation Act 1980, s.96 Land Registration Act 2002, s27 Land Registration Act5 1925, and s.87 Law of Property Act 1925.

    It also considered the mechanisms by which equitable charges are converted into legal charges per s.90 LPA 1925 and Ladup Ltd v Williams And Glynns Bank [1985] 1 W.L.R 851 and Re Thompsons Mortgage Trusts [1920] 1 Ch. 508.

  • P v GT

    Advised as sole junior on the liability of a freehold company under the terms of a lease and sub-lease, for damage caused by an unremedied leak in a block of flats by  one of its lessees, in circumstances where the freeholder was also the sub-lessor of the tenant who suffered damage under that sub-lease. Drafted the Particulars of Claim.

  • Re: an Estate

    Advised as sole junior on the merits of an application for sale pursuant to CPR 73.10C in respect of a high-value freehold property over which there were eight different parties with legal charges or charging orders and where the registry was considerably out of date and now inaccurate as to the relative priority of those charges.

Group Actions and Product Liability

Thom has been involved in some of the largest product liability and group action disputes, including the Volkswagen NOx Emissions litigation.

He is currently instructed in a mass equal pay litigation.

He also has experience in claims under the Data Protection Act 2018, the interplay between the duties of data controllers and processors, as well as in the tort of misuse of private information.


Thom is currently instructed by a large UK retailer in a mass equal pay litigation.

He regularly appears in discrimination and unfair dismissal claims before the ET. He was recently instructed as sole counsel in a claim for indirect discrimination and a failure to make reasonable adjustments against Apple Retail UK Limited.

Given his significant trial experience for a barrister of his call, he has particular strength in claims that require adept witness handling and cross examination.

Intellectual Property

Thom has dealt with high-value claims in soft and hard IP, particularly in claims for breaches of copyright and design rights.

Most recently, he successfully defended a well-known Scottish boat designer at trial in the Intellectual Property Enterprise Court, where the case turned on alleged technical similarities between competing designs for personal high-speed watercraft.

He is also the winner of the Oxford International IP Moot, the largest mooting competition dealing with IP law.

Public Sector

Thom was appointed Junior Counsel to the Crown (C Panel) in 2023 and has advised and represented numerous Government Departments, agencies and related bodies (including the Department of Health and Social Care; the Ministry of Defence; the Ministry of Justice; the Department of Levelling Up, Housing, and Communities; and various London Boroughs).

He is currently instructed by a Government Department in a £140 million contractual dispute with a supplier of goods and services.

Further, he recently appeared in the Divisional Court as junior counsel in London Borough of Barking and Dagenham v Argos Limited [2022] EWHC 1398 (Admin), representing the successful Appellant.

Personal Injury

Thom has assisted leading counsel in high-value claims in negligence, advising on all areas of liability and quantum.

He is experienced in advising on particularly difficult areas of quantum, including injuries to the back, injuries involving the acceleration of pre-existing degenerative conditions, and permanent injuries to the hand and thumb.

He also assisted in the defence to a multi-jurisdictional group action claim arising out of allegations of assault and false imprisonment in two African countries, and has particular knowledge about quantum in international claims in tort.

Health & Safety, and Regulatory

Thom has experience in a range of Health and Safety work, mostly involving fatal accidents. He has an in-depth understanding of the regulatory framework, as well as the special duties and requirements arising as a result of construction contracts.

He is currently instructed by a large chemicals manufacturer and has in the past been instructed as junior counsel by the Ministry of Defence and the government of the Isle of Mann.

He recently appeared in the Divisional Court as junior counsel in London Borough of Barking and Dagenham v Argos Limited [2022] EWHC 1398 (Admin), representing the successful Appellant.

He has extensive criminal trial experience in his own right, and has extensive grounding in all aspects of criminal procedure, from the Magistrates courts up to the Court of Appeal, allowing him to give accurate and effective advice to clients.  He can assist both tactically in the early stages, and at trial.


Instructing Thomas Mallon

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  • Attorney General’s Panel of Counsel – C Panel (01/09/2023 to 31/08/2028)
  • BPTC, City University
  • Middle Temple Quatercentenary Scholarship
  • GDL, City University (Distinction)
  • MA Economics, University of Tokyo
  • Japanese Government MEXT Scholarship
  • BA (Hons) English, University of Oxford
Regulatory Information

All members of Chambers are registered with the Bar Standards Board of England and Wales. For our standard contractual terms click here.

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: 71750

VAT Registration Number: 346120724

Legal Status: Barrister

Professional Insurance: All members of Chambers have professional liability insurance provided by the Bar Mutual Indemnity Fund Ltd. Territorial coverage is world-wide and subject to the term of the Bar Mutual. Click here for details.

Regulated by the Bar Standards Board.

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