Mark Side



Mark is Partner and Head of Dispute Resolution at independent law firm Tanner De Witt. With more than thirty years of experience Mark is a highly awarded litigator whose practice today focuses on contentious regulatory matters with additional experience in matrimonial asset tracing and disputes within professional partnerships. Mark has extensive commercial litigation experience acting for shareholders, high net worth individuals, financial companies, public companies and accountants.

Most recently Mark has conducted landmark employment action in Hong Kong acting for the leaving partner of a well-known Hong Kong firm and for a number of years he has conducted litigation for a major PRC bank handling cases concerning letters of credit and the extent of a banker’s duty of care to customers. Sources regard him as a “strategically very strong, mindful of our concerns and [he] always explains the contributing factors to his advice” (Chambers Asia).

A part of Mark’s work is for the Law Society’s Solicitors Disciplinary Tribunal and the Disciplinary Committee of the Hong Kong Institute of Certified Public Accountants and involves the hearing of professional negligence complaints within these professions.

Another part of Mark’s professional practice involves appearances before the Tribunals and administrative bodies that control the affairs of many regulated professions and industries in Hong Kong.  These include the Liquor Licensing Board, the Municipal Services Appeals Board, the Registration of Persons Tribunal, and the Securities and Futures Appeals Board.

Mark is a CEDR accredited mediator (see the websites at and  Mark is a member of the CEDR Mediation Panel.

Mark was admitted as a solicitor in England and Wales in 1986 and worked in the City of London before moving to Hong Kong in 1992. After qualifying as a solicitor in Hong Kong, Mark worked at two City of London international law firms.  Before joining Tanner De Witt in 2000, Mark headed the litigation department of one of Hong Kong’s largest law firms. He was born in England, studied Philosophy, Politics and Economics at Oxford University.



Key Cases

  • Supervising execution of Anton Piller orders obtained by other parties.
  • Acting for the board of directors in a Hong Kong public company abandoned by chairman involved in cross-border investigations for fraud. Obtaining the appointment of Receivers for the public company and advising on the management of the public company to date.
  • Representing key individuals in Commissions of Enquiry from time to time.
  • Successfully obtaining judgment in favour of siblings deprived of their deceased father’s valuable estate. The action involved the interpretation of the testamentary document and forged company documents.
  • Acting for a former husband to pursue proceedings to vary downwards court ordered maintenance payments.
  • Conducting litigation for a major PRC bank and handled cases concerning letters of credit and the extent of a banker’s duty of care to customers.
  • Conducting landmark employment action in Hong Kong acting for leaving partner of a well-known Hong Kong firm.
  • Acting for a finance professional in a long-term wardship case that involves allegations of sexual abuse and violence towards the child. The case also involves complicated access and financial disputes.
  • Acting for a husband in a case involving divorce, a postnuptial agreement, ongoing issues regarding execution and administration of the post-nuptial agreement.
  • Acting for the husband in a long marriage with complex matrimonial asset valuation issues specifically international commercial and hedge fund structures. Assets are held in Hong Kong, UK and the US.

In recent years Mark has also operated as a mediator and as a solicitor to parties involved in mediations. As a mediator he has served in cases involving:

  • a prominent Italian fashion designer and a member of the Hong Kong Legislative Council;
  • a partnership dispute for a recently established Hong Kong law firm;
  • a claim concerning the sale and purchase of shares in a shipping company;
  • a dispute between toy manufacturers and a departing senior executive;
  • solicitors terminating a long-running partnership;
  • solicitors seeking to settle judgment debts without recourse to bankruptcy.

Speaking Experience

Over the last few years Mark has given talks and presentations in Hong Kong and Asia on commercial litigation, including:

  • Litigation Tactics
  • The Strategic Use of Litigation Procedures
  • Mareva injunctions



Asia Pacific Legal 500 2020 notes: Sources praise Mark Side stands out for his ‘fantastic knowledge’; he leads the team with Jeff Lane and Pamela Mak.

Chambers Asia Pacific 2020 notes: Mark Side‘s “excellent tactical awareness” and report that “his experience and understanding of the bigger picture is valuable in developing a sound litigation strategy.” His broad scope of litigation experience spans contentious regulatory matters, white-collar crime investigations and professional duty disputes.

Asia Pacific Legal 500 2019 notes: Mark Side leads the team at Tanner De Witt, which recently assisted Grant MacEwan University with tracing and recovery of CA$11.8m misappropriated through cyber fraud, with the team facilitating the recovery of approximately CA$4m in Hong Kong through obtaining a series of emergency injunctions and disclosure orders.

Chambers Asia Pacific 2019 notes: Mark Side has a wide-ranging litigation practice that includes expertise in restrictive covenant and professional duty disputes, matrimonial asset tracing and white-collar crime.

Mark is listed as a Leading Lawyer for Dispute Resolution in the 2018 Edition of Asialaw Leading Lawyers.

Chambers Asia Pacific 2018 notes: Mark Side focuses his practice on contentious regulatory matters, with additional experience in matrimonial asset tracing and professional duty disputes. Sources regard him as a well-known Hong Kong practitioner and a “good litigator.”

Chambers Asia Pacific 2017 notes: Mark is a committed mediator and litigator with solid experience in handling major disputes for clients such as public companies, shareholders and accountants. Market sources comment that “he is a good all-rounder who “has been around the market for a long time.”

Asia Pacific Legal 500 2017 notes: The [dispute resolution and litigation] practice at Tanner De Witt is led by Mark Side, who is acting for a high-net-worth individual in a professional negligence claim against an international bank.

Mark is consistently ranked as a ‘Leading Lawyer’ for dispute resolution in Hong Kong by various industry publications, including Chambers Asia Pacific and Asia Pacific Legal 500.

Asialaw Leading Lawyers 2017 notes: “Mark Side is very personable with excellent knowledge of the jurisdiction,” says a client.

2016 notes: “A client appreciates that Mark Side is ‘strategically very strong, mindful of our concerns and always explains the contributing factors to his advice’. He acts for public companies, shareholders and accountants, among others. He is also known for his work as a mediator.”

Asia Pacific Legal 500 2016 notes: “Tanner De Witt attracts very strong peer and client feedback.  Department head Mark Side is ‘very good on licensing and matrimonial issues.'”

Chambers Asia Pacific 2015 notes: “Head of litigation Mark Side is recommended by market sources for his ‘considerable experience. He offers quality, responsiveness and a hands-on service.‘ He often acts on commercial and banking litigation.”

Asia Pacific Legal 500 2015 notes: “Mark Side is adept at representing executives and senior employees in investigations.”

Chambers Asia Pacific 2014 notes: “Mark Side leads the litigation and dispute resolution team. He is regularly appointed to act for members of Hong Kong’s Sindhi business community, and market sources comment on his extremely pleasant manner.”

Asia Pacific Legal 500 2014 notes: “Independent Hong Kong firm Tanner De Witt has a dynamic practice thanks in part to the efforts of senior litigator Mark Side.”

Chambers Asia Pacific 2013 notes: “Litigation head Mark Side specialises in professional negligence matters. He wins plaudits for his responsive style and tactical acumen, while one client remarked: ‘He really cares about his clients and their cases, and has a great bedside manner.’ He is also a CEDR-accredited mediator.

Asia Pacific Legal 500 2013 notes: “Tanner De Witt has a genuinely broad litigation practice, which has been handling a number of negligence and breach of fiduciary duty cases. The eminent Mark Side, Pamela Mak and insolvency expert Ian De Witt are key members of the team.”

Asia Pacific Legal 500 notes: “Though its expertise is much broader than in contentious work, Tanner De Witt truly excels in the litigation environment. This is thanks in part to the presence of immensely experienced litigators Mark Side (‘very good’) and Ian De Witt (‘expert analysis and opinion’).”

Mark is recommended by Asia Law & Practice as a ‘Leading Lawyer’ for Dispute Resolution (2016 and 2015)



  • Foreign Correspondents’ Club, Hong Kong
  • Oxford and Cambridge Society
  • Royal Asiatic Society
  • Hong Kong Family Law Association