About

Jonathan specialises in international contentious trust, probate and succession disputes, high-value family disputes and commercial litigation. He acts for high-net-worth individuals from the UK and around the world, as well as trustees, protectors, wealth managers and multinational businesses.

Jonathan has a wealth of experience litigating in both the English and international courts, including Bermuda, the Cayman Islands, BVI, Jersey, Guernsey, Singapore, the Isle of Man, Gibraltar and Mauritius. He acts on the full range of matters affecting private clients and their structures, including applications to deal with mistaken advice or flawed decisions by way of rectification or revocation; breach of trust claims; fraud claims; disputes between family members regarding their interest in family trusts and the operation of underlying corporate entities; trustee directions and court approval/blessing applications; advice about and disputes involving loss of capacity by family members or fiduciaries; challenges to wills and Inheritance Act claims; and art and cultural property disputes. He has particular expertise in resolving difficult and long-running disputes between beneficiaries of both English and offshore family trusts owning large multinational businesses. 

As well as acting in court and arbitration proceedings, he has also advised clients in numerous successful large-scale settlement negotiations and mediations, particularly in the context of family disputes. Jonathan is a member of the Association of Contentious Trusts and Probate Specialists and a Solicitor Advocate.


His work helping clients resolve mistakes and undo their consequences means Jonathan also frequently acts for claimants on professional negligence claims. He also acts for clients in commercial litigation, with particular expertise in disputes involving breaches of fiduciary duty and conspiracy.

Qualified in England and Wales, 2008.


Experience

  • Acting for the trustee on a court-approved restructuring of substantial trusts, balancing the settlor’s wishes, the current beneficiaries’ needs for segregated assets, and multi-jurisdictional tax issues. The restructuring resolved a number of historic issues without contested litigation.
  • Advising on the settlement and court approval of a long-running dispute between trustees and beneficiaries of a series of substantial offshore trusts concerning both the historic administration of the trusts, disputes between family members about their respective interests, and the management of underlying companies.
  • Acting in relation to a number of claims against trustees for breach of trust relating to the management of investments in trusts worth many hundreds of millions of pounds.
  • Successfully acting for the heir of an international businessperson in relation to claims against other family members for misappropriation and maladministration of assets claimed by our client.
  • Successfully acting for executors in relation to the rectification of a will whose drafting was defective. The matter was resolved without the need for public court proceedings disclosing the identity of the family through the use of an innovative dispute resolution mechanism supported by insurance. The matter also involved professional negligence proceedings against the firm responsible for drafting the will.
  • Acting for a beneficiary in securing the first judgment in Mauritius confirming the ability to revoke dispositions made by mistake, successfully persuading the court to follow the English legal position on this issue.
Jonathan is brilliant. He works night and day to get to a resolution. He doesn’t take bad points, and he is always reassuring to work with.

Chambers HNW 2025

He is very good at dealing with complex, multifaceted litigation.

The UK Legal 500 2026

Jonathan diplomatically navigates his way through the treacherous waters of complex and onerous matters.

Chambers HNW 2025

Jonathan Arr is a superstar. He is the complete package.

Chambers HNW 2025

Jonathan Arr has developed a very strong practice in this area which differs in also specialising in company and fraud elements affecting trusts and estates. He is on a par with an English silk in terms of legal knowledge, but he is also extremely personable.

The Legal 500 2024

Jonathan Arr - seasoned and dynamic litigator who can handle cases of the largest size and complexity.

The UK Legal 500 2026

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