Professional practice

Yanni is developing a broad commercial litigation, civil fraud and arbitration practice in line with Chambers’ profile.

Recent and current instructions include:

  • JSC Commercial Bank PrivatBank v Kolomoisky: Acting for the claimant Ukrainian state-owned bank in a US$1.9bn civil fraud claim (led by Robert Anderson KC, Andrew Hunter KC and Tim Akkouh KC).
  • Trafigura v Gupta & Others: Acting for the Claimants in a claim arising out of an alleged US$600m nickel trading fraud (led by Nathan Pillow KC and David Peters KC).
  • Hoffman and Greenbaum v Finalto Group Limited and Gopher Investments: Acting for the Defendants in a multi-million dollar fintech dispute involving claims for breach of contract, breach of fiduciary duty and fraudulent misrepresentation (led by Paul Downes KC).
  • Acting for the Defendants in a s 67 Arbitration Act challenge to the award of an investment tribunal against a Gulf state (led by Graham Dunning KC).
  • Acting in a contractual dispute relating to aircraft tyres which delaminated upon take-off, causing around £16 million of damage to the aircraft (led by Ciaran Keller KC).
  • Acting for a major US medical technology supplier defending a substantial LCIA claim arising out of an international distribution agreement (led by Siddharth Dhar KC).
  • Acting for a ship owner in an application for an anti-arbitration injunction against a sub-sub-charterer in the Commercial Court (led by Christopher Smith KC).
  • Acting for a high net worth individual in a LCIA claim relating to a Greek inheritance dispute (led by Tariq Baloch KC).
  • Acting in a high value employment related dispute in the field of cryptocurrency and high frequency trading (with John Robb).

Before joining Essex Court Chambers, Yanni practised as a barrister in Australia, where he gained experience in a broad variety of commercial matters. He also worked as an associate in the disputes and investigations team at Slaughter and May in London, where he acted on a number of complex and high value commercial disputes often involving issues of foreign law.

Yanni holds a Bachelor of Civil Law with Distinction from the University of Oxford, where he was awarded the Linklaters Prize for Best Performance in Principles of Financial Regulation. He also has a Bachelor of Laws (First Class Honours) and a Bachelor of Commerce (First Class Honours) from Monash University.

 

Career

2024: Tenant, Essex Court Chambers

2023–2024: Pupil, Essex Court Chambers (with Siddharth Dhar KC)

2023: Called to the Bar England and Wales (Lincoln’s Inn)

2022: Called to the Bar, Victoria, Australia

2020–2022: Associate, Slaughter and May

2017–2020: Solicitor, King & Wood Mallesons

2017: Admitted as a solicitor, Australia

Education

2019–2020: BCL, University of Oxford (Distinction)

2011–2016: Bachelor of Laws, Monash University (First Class Honours)

2011–2016: Bachelor of Commerce, Monash University (Finance major; First Class Honours)

Awards

2020: Linklaters Prize for Best Performance in Principles of Financial Regulation in BCL

2016: Best delegate award at Harvard World Model United Nations in Rome, Italy

2015: Best delegate award at Harvard World Model United Nations in Seoul, South Korea

2015: Winner of Microsoft Protégé Consulting Challenge

2014: Winner of Monash University General Moot Competition

Publications

Yanni is the current editor of Thomson Reuters Westlaw’s ‘Trusts’ entry in The Laws of Australia.

Yanni has also published the following pieces in leading English journals:

  • Y Goutzamanis, “Foreign illegality in cross-border payments: the rule in Ralli Bros” (2025) 6 Journal of International Banking and Financial Law 415
  • Y Goutzamanis, “Closing the Floodgates: Lloyd v Google LLC [2021] UKSC 50” (2023) 86 Modern Law Review 249
  • Y Goutzamanis, “Rise of the Privacy Class Action” (2020) 39 Civil Justice Quarterly 203
Arbitration & related court applications

Recent arbitration related instructions include:

  • Acting for a major US medical technology supplier defending a substantial LCIA claim arising out of an international distribution agreement.
  • Acting for a respondent in an LCIA claim arising out of various employment (and related) contracts in the field of cryptocurrency and high frequency trading.
  • Acting for a high net worth individual in an LCIA arbitration relating to an ongoing inheritance dispute in Greece.
  • Acting for a medical research organisation in an arbitration under World Intellectual Property Organization rules involving a dispute arising out of a sponsorship agreement for medical research.
  • Acting for a ship owner in an application for an anti-arbitration injunction and other declaratory relief against a sub-sub-charterer in the Commercial Court.
  • Acting for an investor in a s 67 Arbitration Act challenge to the award of an investment tribunal against a Gulf state.

Yanni has presented at Paris Arbitration Week on the interpretation of investment treaties in English Court challenges to arbitration awards.

Banking & financial services

During pupillage Yanni worked on a number of banking and financial services matters, including:

  • Credit Suisse Life (Bermuda) Ltd v Bidzina Ivanishvili and others: An appeal to the Privy Council against a judgment of the Bermudan Court of Appeal on claims arising out of the investment of substantial funds in insurance policy investment structure.
  • The provision of advice on the application of a parallel debt regime in a high-value facility agreement.
  • Various sanctions disputes, including Celestial Aviation Services v UniCredit, which concerned the effect of UK/EU/US sanctions on the enforceability of a letter of credit.
  • Drafting an Answer to a claim against a bank for alleged breach of a Quincecare duty in the Royal Court of Jersey.
  • Advice on potential claims arising from the grant of restricted share units.

Yanni also has significant banking and financial services experience from his work as a barrister in Australia and, prior to that, as an associate at Slaughter and May in London. Banking and financial services disputes in which Yanni was instructed in Australia include:

  • Equity Financial Planners Pty Ltd v AMP Financial Planning Pty Ltd – acted for a large diversified financial services company in defending a class action brought by former financial planners in the Federal Court of Australia (led by David Batt KC and Tamieka Spencer Bruce SC).
  • In the matter of Redstar Transport Operations Pty Ltd (in liq) & Ors – acted for PwC as liquidators of the Redstar Group of Companies in applications for public examination of a receiver and auctioneer in the Supreme Court of Victoria (unled).
  • Providing advice to a major Australian bank relating to a payment processing error (led by Dr Charles Parkinson KC).

Yanni was also awarded the Linklaters prize for the highest mark in the Principles of Financial Regulation paper on the BCL at Oxford.

Civil Fraud & Asset Tracing

Yanni has experience working on high-value civil fraud matters. He is currently instructed in:

  • An upcoming six day consequentials hearing in a US$1.9bn civil fraud claim: JSC Commercial Bank PrivatBank v Kolomoisky.
  • An upcoming six week Commercial Court trial in a $500m+ claim arising out of a high-profile alleged nickel fraud: Trafigura v Gupta & Others.
  • A multi-million dollar fintech dispute involving allegations of breach of fiduciary duty and fraudulent misrepresentation: Hoffman and Greenbaum v Finalto Group Limited and Gopher Investments.

Yanni also has experience in contempt proceedings and advising on worldwide freezing orders (including Chabra orders).

Commercial dispute resolution

Yanni has advised and acted in a wide range of commercial disputes both as sole and junior counsel and in litigation and arbitration. His recent and current instructions include:

  • Hoffman and Greenbaum v Finalto Group Limited and Gopher Investments: Acting for the Defendants in a multi-million dollar fintech dispute involving claims for breach of contract, breach of fiduciary duty and fraudulent misrepresentation.
  • Acting in a contractual dispute relating to aircraft tyres which delaminated upon take-off, causing around £16 million of damage to the aircraft.
  • Acting for a major US medical technology supplier defending a substantial LCIA claim arising out of an international distribution agreement.
  • Advising and preparing particulars of claim for a high net worth individual in relation to the supply of goods and construction services (unled).
  • Advising (unled) a Polish transport/logistics company in relation to potential negligence claims stemming from a fatal accident on UK roads.
  • Acting (unled) for Qatar Airways in relation to a substantial lost baggage claim.
  • Acting (unled) for a marketing agency defending a default judgment set aside application in the County Court.

Yanni also has significant commercial dispute resolution experience from his work as a barrister in Australia and, prior to that, as an associate at Slaughter and May in London.

Conflict of laws & private international law

The majority of Yanni’s work involves a significant international element and conflicts of laws issues. Recent examples include:

  • Advising (with Paul McGrath KC) on jurisdiction in a stay application in Cyprus proceedings.
  • Assisting David Baker (of Kellerhals Carrard) with a Ralli Brothers argument in a LCIA arbitration relating to various financing agreements.
  • Hoffman and Greenbaum v Finalto Group Limited and Gopher Investments: Acting for the Defendants in a multi-million dollar fintech dispute involving issues of Israeli law.

During pupillage, Yanni gained exposure to a number of cases involving issues of private international law, including:

  • Drafting a skeleton argument in a jurisdiction challenge in the Commercial Court.
  • Providing merits advice on an application for an anti-suit injunction in complex multi-jurisdictional proceedings arising out of a bond issue.

Celestial Aviation Services v UniCredit: An appeal involving various issues of UK/EU/US sanctions law and the effect of illegality under foreign sanctions on the enforceability of the English law governed letter of credit.

Energy & natural resources

Yanni is currently instructed in relation to an upcoming six week Commercial Court trial in a $500m+ claim arising out of a high-profile alleged nickel fraud: Trafigura v Gupta & Others.

During pupillage, Yanni gained exposure to a number of energy & natural resources disputes, including:

  • Assisting Siddharth Dhar KC in an LCIA arbitration arising out of a sale of crude oil.
  • Advising on a claim arising out of a sale of gasoil.
Insurance & reinsurance

During pupillage, Yanni gained exposure to the following insurance and reinsurance matters, including:

  • Technip Saudi Arabia Limited v The Mediterranean and Gulf Cooperative Insurance and Reinsurance Company: An appeal regarding the construction of an offshore construction all-risks insurance policy.
  • A mediation in a dispute regarding coverage under a crime and civil liability insurance policy.
  • Advice on the application of the Bermudan Segregated Accounts Companies Act 2000 to a reinsurance policy.
  • Advice on whether an insurer could retrospectively reallocate losses under a tower of excess of loss contracts.
  • Advice on the operation of a trends clause in a Covid BI Policy.
Offshore Litigation

Yanni has experience with various Bermudan law matters and, in particular, the Bermudan Segregated Accounts Companies Act 2000. He also has experience drafting an Answer to a claim against a bank for alleged breach of a Quincecare duty in the Royal Court of Jersey.

Shipping & admiralty

Yanni is currently acting for a ship owner in an application for an anti-arbitration injunction against a sub-sub-charterer in a dispute relating to a vessel grounding (led by Christopher Smith KC). He is also acting for the claimants in an upcoming six week Commercial Court trial in a $500m+ claim arising out of a high-profile alleged nickel fraud at which allegations relating to Bills of Lading, Certificates of Analysis and HS Codes are central to the defence: Trafigura v Gupta & Others.

Unjust enrichment & restitution claims

Yanni has a particular interest in unjust enrichment, having studied the subject on the BCL at the University of Oxford.

During pupillage, Yanni gained exposure to a number of unjust enrichment matters, including:

  • Drafting a skeleton argument in a jurisdiction challenge in an unjust enrichment claim in the Commercial Court.
  • Advising on the merits of an unjust enrichment claim.

Yanni has also been instructed on significant restitution claims in Australia, including ConnectEast Pty Ltd v CityLink Melbourne Limited where he acted for CityLink Melbourne Limited in defending a claim for restitution of a roaming fee allegedly charged in excess of a statutory cap in the Supreme Court of Victoria (led by Jeffery Gleeson KC and Albert Dinelli KC).