Arianne King

CEO and Solicitor Advocate

Arianne King CEO and Gaming Solicitor at Costigan King

Expertise

  • Gaming & Betting

  • Commercial Litigation

  • Corporate & Commercial

  • Construction & Energy

  • Fintech

  • Blockchain & Digital Assets

  • Dispute Resolution

Recognition

  • Ranked in Chambers & Partners for Gaming

  • Ranked in Legal 500 for Gaming & Betting

  • Ranked in Legal 500 for Commercial Litigation mid-market

  • Member of the IAGA (International Association of Gaming Advisors)

  • 'Most Influential Woman in Commercial Law 2019' in Acquisition International's Global Excellence Awards.

Arianne King is a Solicitor Advocate specialising in complex commercial matters across the UK and internationally. Ranked in Chambers & Partners for Gaming and in The Legal 500 for Gaming & Betting and Commercial Litigation (Mid-Market), she is described by Chambers as “a legal dynamo.”

She advises on high-value transactions and strategic regulatory matters, including debt and equity financing, restructuring, cross-border commercial agreements, intellectual property, acquisitions and regulatory compliance involving the FCA, DFSA, the Gambling Commission and the SEC. Her advice is recognised as “genuinely commercial and highly detailed, yet digestible,” combining technical precision with clear strategic direction.

Arianne is particularly known for her work in the gambling and online gaming sector. Legal 500 describes her as “unparalleled in her understanding of the betting and gaming world,” noting that she is “an immersed lawyer and participant in the sector who knows everyone and really fights for her clients.” She has extensive experience representing operators in investigations initiated by the Gambling Commission and advising on complex commercial transactions in online gaming.

In contentious matters, Arianne represents domestic and international clients in complex, high-value disputes across litigation, arbitration, adjudication and mediation. She is described as “a formidable solicitor who cares for her clients and is a constant source of support,” and is regularly instructed where financial and reputational stakes are significant.

Alongside her transactional and contentious practice, Arianne has developed a specialist focus on blockchain technology and digital assets. She advises on regulatory structuring, commercial strategy and dispute resolution in emerging technology sectors and is a recognised commentator on cryptocurrency, regulation and tax.

She was named “Most Influential Woman in Commercial Law – UK” in Acquisition International’s Global Excellence Awards.

Legal 500 notes that she “always puts the client first and goes above and beyond to make sure they understand the process,” and appreciate her “straight-talking approach” and the “excellent and thorough service” she provides.

Expertise

  • Arianne has significant experience in dispute resolution and, particularly, commercial litigation. She has acted for both domestic and international clients in respect of a wide array of complex, high-value disputes in multiple jurisdictions including the UK, Europe, the Caribbean, UAE, DIFC, East Africa, Latin America and Cyprus.

    Arianne acts for clients across a broad range of practice areas, including: banking and finance; corporate (including shareholder disputes); commercial; construction and energy;  intellectual property; professional negligence and regulation and compliance.

    Arianne has acted as lead partner many high-profile, high-value and complex cases – with many having an international aspect. She is ranked in Legal500 for her ‘direct approach and no-nonsense attitude’ and her ability to provide an ‘innovative and personalised service’ for her clients.

  • Arianne specialises in commercial law both nationally and internationally. She advises clients on all aspects of corporate and commercial law, including mergers & acquisitions, financing (debt and equity), secured lending, re-structuring, domestic and cross-border commercial agreements, intellectual property, domestic and cross-border acquisitions and matters of regulation and compliance (including in respect of the FCA, DFSA, the Gambling Commission and the SEC).

    She has considerable experience of corporate and commercial matters over a broad range of industries. She has acted for domestic and international clients, including in respect of high-value, multi-jurisdictional acquisitions, with a specialism in offshore structuring.

    Arianne has significant experience is addressing cross-jurisdictional complexities. She has worked on deals spanning Europe, North America, Canada, the Caribbean, Asia, the Middle East and Africa. She has significant experience in working in Cyprus (North and South), Curacao, Malta, Gibraltar and the Isle of Man.

    She is familiar with transacting with private and listed companies on various global markets and the associated procedural and regulatory requirements. At present, she is instructed in respect of multiple corporate transactions in the cryptocurrency, blockchain and gaming sectors – being areas she has developed a specialist practice over recent years.

    Arianne is ranked in Legal500 for her ‘direct approach and no-nonsense attitude’ and her ability to provide an ‘innovative and personalised service’ for her clients. She is also ranked in Chambers for her ‘excellent and thorough service’, ability to ‘always put the client first’ and provide advice which is ‘always genuinely commercial and highly detailed, yet digestible’.

  • Arianne has significant experience in resolving disputes through litigation, arbitration, adjudication, mediation and expert determination. She has acted for both domestic and international clients in respect of a wide array of complex, high-value disputes in multiple jurisdictions including the UK, Europe, the Caribbean, UAE, DIFC, East Africa, Latin America and Cyprus.

    She acts for clients across a broad range of practice areas, including banking and finance; corporate (including shareholder disputes), commercial; intellectual property; professional negligence and regulation and compliance.

     Arianne is ranked in Legal500 for her ‘direct approach and no-nonsense attitude’ and her ability to provide an ‘innovative and personalised service’ for her clients.

  • Arianne has significant experience in acting in the blockchain sphere and is able to advise on all aspects relevant to the space. Her innovative approach has led her to advise on complex and often first-in-kind matters in the blockchain sector. She understands the importance of approaching matters with the same level of innovation as our clients.

    Arianne’s experience spans across all matters of fintech, crypto assets and digital currency from start-ups to restructuring and flotations by way of ICO and IPO. She has a wealth of experience in advising in commercial transactions, including in respect of intellectual property and data protection.

    She also provides advice on all matters of regulation and is able to advise on all matters of compliance both domestically and internationally.

    Arianne has advised on the legal aspects of launching and building cryptocurrency and blockchain related businesses, provided legal support on business plans and white papers; ICO Terms and Conditions; Cryptocurrency Purchasing Agreements including advice on payment terms; Cryptocurrency Escrow Agreements; Cryptocurrency Exchange Terms and Conditions; consultancy agreements; intellectual property matters; advice on escrow between parties for receiving and paying with cryptocurrencies and AML and KYC requirements. She has also advised a blockchain company in respect of a reverse takeover, allowing it to be listed on the New York Stock Exchange.

    She adopts a practical, commercial and efficient approach and has the ability to provide a fast and effective service across multi-jurisdictional matters.

  • Arianne truly understands the regulatory and commercial environment in which the gambling sector operates across multiple jurisdictions.

    She appreciates the commercial objectives of her clients and the importance of balancing these objectives with regulatory requirements.

    She has extensive experience in managing and advising on complex, cross-border transactions, with vast experience in working in Australia, Gibraltar, Malta, Cyprus (North and South), the Isle of Man, Curacao, Canada, the USA, Panama, the Philippines, Mauritius, the Seychelles, and Singapore. Her familiarity with local and international regulations means she has multi-jurisdictional capabilities and assists both UK and international clients in dealing effectively with all gaming related matters.

    She offers advice on all aspects relevant to gaming and betting operations, including:

    • commercial transactions in online gaming – covering sportsbook and casino operations in the UK and worldwide;

    • advising as to matters of intellectual property;

    • advising in respect of questions of regulation and compliance, domestically and internationally;

    • acting on behalf of operators as to investigations brought by the Gambling Commission;

    • acting for operators and customers in respect of alleged regulatory failings (money laundering and safer gambling related);

    • preparing policies and accompanying training for operators in order to ensure compliance with regulatory requirements; and

    • advising in respect of matters concerning data processing and data protection.

    She is ranked for Gaming and Betting in the Legal 500 and Gaming in Chambers and Partners.

  • “Arianne King is a legal dynamo.”

    Chambers & Partners

  • “Arianne King gives everything a personal touch and I am very satisfied with the service I get from her.”

    Chambers & Partners

  • “Arianne always puts the client first and goes above and beyond to make sure the client understands the process. Her in-depth knowledge and vast experience in this sector and the law are invaluable.”

    Chambers & Partners

  • "Arianne has been our lawyer since the beginning and is excellent, I can't speak highly enough."

  • "Arianne provides an excellent and thorough service and we very much appreciate her straight-talking approach."

    Legal 500

  • "Arianne King always puts the client first and goes above and beyond to make sure they understand the process."

    Chambers 2024

  • "Arianne's in-depth knowledge and vast experience in this sector and the law are invaluable. Her advice is always genuinely commercial and highly detailed, yet digestible."

    Chambers & Partners

  • "Arianne is a formidable solicitor who cares for her clients and is a constant source of support."

    Legal500

  • "Arianne King of Costigan King is adept at assisting international clients with establishing new gaming businesses. She advises on a range of regulatory and compliance matters, in addition to providing expertise in connection with licensing and commercial mandates."

    Chambers & Partners 2025

  • "Arianne provides an excellent and thorough service and we very much appreciate her straight-talking approach."

    Legal500

  • “Arianne King leads the team and is a gambling specialist with extensive experience representing operators in investigations initiated by the Gambling Commission and advising on commercial transactions in online gaming.”

    Legal500

  • “Arianne King is unparalleled in her understanding of the betting and gaming world. She is an immersed lawyer and participant in the sector who knows everyone and really fights for her clients.”

    Legal500

  • "Arianne & her team handled the sale of our European marketing business to a large US firm. The sale, & subsequent 3-year earn-out, went smoothly thanks in large part to the excellent job they did in protecting our interests & diligently & efficiently handling all legal aspects of the transaction."

    Eleven Hundred Agency