Julian Hayes

“He knows the law inside out and then uses that knowledge to great effect for his clients, translating the black letter law into practical outcomes for his clients.” 

Chambers UK

Julian is a specialist in surveillance and data protection law, including advising tech firms, social media companies and other communications service providers on law enforcement demands for data, the use of new technologies for investigative purposes, and the enforcement of data rights and obligations. He has extensive experience of financial crime and regulatory investigations, including bribery and corruption, fraud, insider dealing and market abuse, customs & excise offences, and anti-competitive practices. Julian writes and speaks on a variety of topics, principally relating to information law topics.

Surveillance and Information Gathering Legislation

Julian is a partner in the firm’s highly ranked data protection and information law team, advising telecommunications operators on:

  • obligations in relation to warrants and notices issued under the Investigatory Powers Act 2016, including regarding interception and communications data;
  • surveillance powers under Regulation of Investigatory Powers Act 2000;
  • law enforcement activities under the Police Act 1997;
  • complaints to the Investigatory Powers Tribunal; and
  • the provisions of the Crime (Overseas Production Orders) Act 2019 and the UK/US Data Access Agreement.

Data Protection Legislation

Julian is noted for his expertise in data protection law, including:

  • obligations on data controllers under the UK GDPR and the Data Protection Act 2018, including data protection compliance, policy reviews, and data processing agreements;
  • data breach reporting, including in the aftermath of cyberattacks;
  • offences under data protection legislation, including the unlawful obtaining (blagging), re-identification and alteration of personal data;
  • voluntary provision of personal data to law enforcement authorities, including lawful processing, transparency and data minimisation;
  • law enforcement processing of personal data;
  • ICO enforcement action, including information notices, and entry & inspection powers; and
  • data subject rights, including data subject access requests, rectification, and erasure.

Interception, Communications and Computer Misuse Offences

Julian’s practice encompasses:

  • unlawful interception under investigatory powers and wireless telegraphy legislation;
  • offences involving the improper use of electronic communications networks, including under the Communications Act 2003 and Malicious Communications Act 1988; and
  • offences under the Computer Misuse Act 1990, including unauthorised access to computer data (hacking), to commit further offences, and to impair computer operation.

Financial Crime and Regulatory Investigations

Julian is experienced in advising on financial crime and regulatory matters, including:

  • SFO investigations for bribery and corruption, including the use of s.2 powers under the Criminal Justice Act 1987;
  • FCA investigations for insider dealing, market abuse and market manipulation;
  • CMA investigations for breaches of the Competition Act 1998 (Chapter I prohibition);
  • HMRC investigations for offences under the Customs and Excise Management Act 1979 and at common law, including the use of HMRC’s compulsory disclosure notice powers;
  • Code of Practice 9/Contractual Disclosure Facility procedures;
  • Electoral Commission enquiries;
  • defending prosecutions under the Proceeds of Crime Act 2002; and
  • Internal investigations on behalf of corporates and governmental organisations.


Additional areas of expertise include:

  • judicial review proceedings against law enforcement agencies;
  • Norwich Pharmacal applications in the High Court;
  • defending complaints against corporates for breaches of the OECD’s Guidelines for Multinational Enterprises; and
  • duties under online harms measures, including the Children’s Code / Age Appropriate Design Code.


Julian presents on information law matters. Recent speaking engagements include:

  • Fraud Lawyers Association / EFCL Conference – London (2022).
  • International Bar Association’s Transnational Crime Conference – London (2022).
  • American Bar Association’s Criminal Justice Section – Frankfurt (2022).
  • Deutsche Strafverteidiger Verein – online (2021).
  • University College London, Privacy and Data Law & Practice Conference (2021).
  • European Criminal Bar Association – Nice (2018).


Julian’s publications include:

  • GIR’s Guide to Cyber Investigations: Investigations in England & Wales – A Practitioner’s Perspective.
  • Preparing for the worst but operating at our best – reform of the NIS Regulations (The Barrister Magazine, with Andrew Watson, May 2022).
  • UK GDPR reform – buccaneering Britain goads the data protection bear (Police Professional, with Umar Azmeh, Oct. 2021).
  • Online safety – the ICO’s Children’s Code (Open Access Government, September 2021).
  • COVID Status Certificates – a passport to freedom? (The Barrister Magazine, June 2021).
  • Algorithmic policing – trust is a must, not a nice to have (Global Data Review, with Suzanne Gallagher, May 2021).
  • The online harms bill misses the point (The Times, with Michael Drury, Jan. 2021).

Professional Memberships

  • Fraud Lawyers Association (Executive Committee Member)
  • European Criminal Bar Association (E-evidence working group member)
  • The Law Society


Following an undergraduate degree in history, Julian completed post-graduate legal studies in Newcastle before training as a barrister at a leading criminal/regulatory chambers. He then worked as a regulator at the London Stock Exchange before moving to Australia where he spent several years undertaking high profile litigation at an international law firm. After returning to the UK and joining BCL, Julian became a partner in 2017.

Julian speaks German (intermediate).

What the directories have said:

“He is very intelligent and dedicated. He also works strategically and is solution-oriented, and he only works in the interest of the client; not just trying to make money…He works mostly in the field of data protection and is very knowledgeable on e-evidence, which is quite unusual. He has special knowledge in the field.

Chambers UK, 2023

“His knowledge of the subject was exceptional and we found him to be a genuine expert in the field. He went over and above that which we expected of him to provide quick and informative advice. He was extremely professional at all times, so we couldn’t have asked for more. Overall, his client service, commercial awareness and level of sophistication are all very strong.

Chambers UK, 2023

“Julian is an excellent financial crime lawyer. He is strategic, meticulous and forward-thinking. He manages complex parallel issues with great skill.

Chambers UK, 2023

“Julian does lots of work in financial services and has those type of clients. His ranking is right.

Chambers UK, 2023

“Julian Hayes is really good. I would definitely put him higher as a group.

Chambers UK, 2023

“He does very good things and I would refer to him, certainly.

Chambers UK, 2023

Julian Hayes is a strategic, meticulous and forward-thinking lawyer.

Chambers UK, 2023

Julian is our go-to lawyer on UK law matters. He is an expert on data protection matters. He is always approachable, efficient, and practical.

Legal 500, 2023

Julian Hayes has a deep understanding of data protection, privacy and cybersecurity. He also has a global awareness and perspective of how current issues are dealt with in other countries. He is the first person I phone when I need to discuss issues or bounce ideas around. He has an intuitive feel for the subject, backed up by sound knowledge and judgement.

Legal 500, 2023

Julian Hayes is a very driven and hardworking partner who manages to combine his fierce intellect with charm and a friendly persona. He is excellent with clients and knows how to get to the root of a problem.

Legal 500, 2023

Julian Hayes is a creative lawyer with a good instinct for the law, which is absolutely key in this field.

Legal 500, 2023

“Julian Hayes’ client service and general level of service, level of sophistication and commercial awareness are all very strong.”

Chambers HNW, 2022

“He is pragmatic and client-friendly.”

Chambers UK, 2022

“He is a brilliant lawyer.”

Chambers UK, 2022

“It is always a pleasure to work with him, as he is very collegial and a very good lawyer. He has an enquiring mind and always figures out the client’s best interests and how to achieve them as optimally as possible. Julian Hayes is a specialist in the only recently newly regulated field of computer misuse offences, data protection, the regulation of artificial intelligence and online harms. He also has published several thought-leadership articles in relation to these topics.”

Chambers UK, 2022

“Julian is very knowledgeable and a delight to work with. He knows the law inside out and then uses that knowledge to great effect for his clients, translating the black letter law into practical outcomes for his clients.”

Chambers UK, 2022

“in data protection. The ICO are increasingly taking a criminal enforcement type role, and he definitely fills that gap in the market, advising on the overlap. He also takes a kind and friendly approach with clients and counsel – he is very personable.

He is very good on criminal procedure and is a very, very useful resource on data protection and cyber issues.”

Chambers UK, 2022

“Julian Hayes will outwork anyone.”

The Legal 500, 2021

“Julian is exceptionally bright and he will work tirelessly for his clients. Owing to his hard work, every aspect of the client’s case is presented in the best way it can be.

The Legal 500, 2021

“Julian has his finger on the pulse when it comes to data law developments. He is gentle but fiercely intelligent.”

The Legal 500, 2020

“…Julian Hayes, who is very competent, clever and also very nice to work with, because he is very reliable and always friendly. He has a keen interest in the area of data regulation and privacy.”

The Legal 500, 2020

Articles by Julian Hayes

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