Trusted Partner
Contentious Regulatory, Litigation & Investigations Law

Allen & Overy LLP

As one of the world’s leading disputes practices, Allen & Overy has vast experience of bringing and defending complex commercial litigation and representing corporations and individuals in the most high profile regulatory and criminal investigations.

We have extensive experience of advising investors across a range of issues, from due diligence, to compliance with evolving legal and regulatory requirements and handling enforcement issues and litigation when things do not go to plan. We see it as a key part of our role as trusted advisors to help our clients to horizon scan and issue-spot, so they are well prepared to adapt and comply with rapidly evolving legislation and regulation. We work closely with our regulatory colleagues to achieve this, helping clients stay abreast of developments in fast developing areas like DLT/Blockchain and crypto-assets or cannabis products, as well as helping them assess the impact of new legislation such as the Online Safety Bill or the National Security & Investment Law and to comply with existing regulation such as the Proceeds of Crime Act.

We have litigation and investigations capabilities in 22 countries, including over 120 litigation and investigations lawyers based in London. We are recognised for protecting clients’ interests across the full range of contentious issues that a business or investor may encounter, handling the full range of corporate and commercial disputes, including contractual claims, bankruptcy and insolvency litigation, class actions and group litigation, insurance litigation, securities litigation, competition and antitrust litigation and employment litigation.  We are experienced in defending clients in investigations by the major criminal and regulatory authorities into the key issues that can give rise to enforcement action against commercial enterprises in both regulated and non-regulated sectors.

This offering, when combined with our ability to work with expert colleagues across a range of complementary parallel practice specialisms, such as employment law, antitrust and competition, data privacy, regulatory advisory, trade law and insurance, means we are ideally placed to help clients solve their problems.

What we specialise in:

Investigations and Regulatory Enforcement

In the UK, we are known for our involvement in some of the biggest, most complex and high-profile regulatory investigations in the market. We act as trusted advisers to a significant number of the biggest household name clients as well as company directors and advisors, who turn to us to guide them through their most sensitive, high-stakes and complex criminal, regulatory and internal investigations.

We advise on the full range of business crime issues and have leading criminal and regulatory defence capability covering anti-corruption and bribery, anti-money laundering, fraud, tax evasion, antitrust, sanctions, market manipulation, mis-selling, cyber-security, data privacy and systems and controls failings. We have particular experience of handling investigations by the UK Financial Conduct Authority (FCA), the Prudential Regulatory Authority (PRA), Revenue and Customs (HMRC) and the Serious Fraud Office (SFO), often with a cross-border component. We have market leading expertise in advising financial services clients on individual accountability, the implementation of the Senior Managers and Certification Regime (SMCR) and investigations into non-financial misconduct, such as bullying, harassment, sexual misconduct and discrimination, and cultural issues.


Our disputes practice is renowned for handling high value, complex and business critical cases that are frequently cross-border in nature. Our litigators represent clients in the most significant courts around the world, delivering commercial, holistic advice quickly, wherever disputes take place.

We represent individuals, investors, national and multinational corporates, and the world’s leading financial institutions and financial services companies, tailoring our approach to the unique requirements of every case. We have particular experience of advising parties to corporate transactions on claims arising out of transactions. We have the full range of specialist expertise within the team to assess and evaluate every aspect of a dispute, devising legal strategies that deliver results in line with our clients’ commercial objectives.

Market recognition

We are recognised by the main legal directories as leaders in litigation and investigations, with feedback noting that “it’s an extremely professional team – they’re always available, responsive and give pragmatic but robust advice” (Chambers UK 2022, Financial Services Contentious Regulatory) and “we have worked with the litigation team and they knocked it out of the park – they took charge and provided a muscular and robust response” (Chambers UK 2022, Litigation). We are ranked in Band 1 for Litigation and Contentious Regulatory Investigations in Chambers UK, Tier 1 for both Financial Services Contentious Regulatory and Fraud: Civil in Legal 500 UK and as one of the top 30 investigations practices globally by Global Investigations Review.

Keeping you updated

In our Investigations Insight blog we provide practitioner insight in relation to the latest trends, risks and developments in business crime and financial services investigations. The blog features views and commentary from members of our global investigations practice. To subscribe please visit:

In our Compact Contract blog we highlight important recent cases relating to contract law, with views and commentary from members of our Litigation & investigations team.  To subscribe please visit:

To view and register to attend upcoming A&O seminars and webinars, please visit:

Some recent publications that may be of interest:

Cross-Border White Collar Crime and Investigations Review

Economic Crime Act – what businesses need to know

The Market Abuse Regulation: the First Five Years

The National Security and Investment Act (NSIA): a date is set

For further advice and assistance please contact:

Allen & Overy LLP
One Bishops Square
E1 6AD
Tel: +44 (0)20 3088 1594
Contact: Harriet Lake

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