Clifford Chance
Simon is a partner in Clifford Chance’s Tech Group, based in London. He has over two decades of experience helping clients find positive solutions to complex legal and regulatory challenges.
Simon regularly supports clients on a range of issues including data protection and privacy, cyber security, digital regulation, AI and data ethics, banking secrecy, and the structuring and negotiation of complex commercial, outsourcing and IT transformation transactions.
Prior to joining Clifford Chance, Simon held a number of in-house legal, regulatory and commercial strategic management roles.
Simon advises clients across a range of sectors including financial services, life sciences, telecoms, technology and retail.
- a U.S.-headquartered bank on the design and implementation of its firmwide GDPR compliance programme
- a leading private equity firm on the design and implementation of its global data governance framework project
- a corporate client on the potential application of the forthcoming NIS2 Directive to its business, including undertaking a gap analysis and planning implementation across the EU
- a leading private equity firm on the use of data analytics to enhance value across its portfolio companies
- a U.S.-headquartered financial institution on the design of a framework for transfers of personal data in the context of regulatory investigations, exchange disclosures and disputes
- various corporate enterprises, banks and financial investors in relation to requests from a third country regulators for the disclosure of personal data on directors and employees in the context of antitrust, criminal and regulatory investigations and disputes
- a UK-headquartered bank on the design and implementation of its global framework for data retention
- a U.S.-headquartered global financial institution on the lawfulness and the collection and processing of D&I data for the purposes of managing affinity networks
- a leading global pharmaceutical company on the development and implementation of a third-party data sharing contractual framework covering clinical trials, pharmacovigilance and vendor relationships
- a leading AdTech company in relation to enforcement activity in multiple jurisdictions alleging breaches of data protection and interception laws
- a UK-listed corporate enterprise in relation to a ransomware attack, including notifying data protection authorities and affected individuals in multiple jurisdictions, supporting during regulatory investigations and assessing contractual liabilities
- a U.S. headquartered technology company in relation to a ransomware attack affecting a vendor, including making regulatory notifications across 21 jurisdictions
- a communications provider in relation to a cyber incident affecting customer payment data, including making notifications to data protection regulators and affected individuals
- a UK-headquartered global financial institution in relation to its negotiations with a leading provider of cloud-based services for the strategic commercialisation of a novel business model
- a mobile network operator on negotiations with competitors to create a single national RAN-sharing entity, serving all mobile network operators
News and client work
Contact details
- Clifford Chance, London
- +442070063060
- Email me
- Follow me on LinkedIn
Career and qualifications
- University College London, LLB 1998
- The College of Law, London, LPC 1999
Awards and citations
- Partner Simon Persoff doesn’t sit on the fence – he sets out your options and identifies the option he recommends. That is what clients need in practice – clear, considered, pragmatic and expert advice.
Legal 500 UK 2024 - Data Protection, Privacy And Cybersecurity – Tier 2 - Simon Persoff is fiercely intelligent and has an encyclopaedic knowledge of data protection law. He brings enormous drive and dedication to all his mandates.
Legal 500 UK 2024 - Data Protection, Privacy And Cybersecurity – Tier 2 - A very competent and robust lawyer who can exceed expectations, every time.
Chambers and Partners UK 2024 - Data Protection and Information Law - Simon has powerful commercial nous in addition to his excellent technical and client relationship skills.
Chambers and Partners UK 2024 - Data Protection and Information Law - Simon has provided insightful and strategic advice.
Chambers and Partners UK 2024 - Data Protection and Information Law - Simon Persoff is a hugely committed partner with deep knowledge of data, privacy and cybersecurity matters. Incredibly hard working.
Legal 500 UK 2023 - Data Protection, Privacy And Cybersecurity – Tier 2 - Simon Persoff has impressed with his technical and practical knowledge. When it really matters, he is there to support us. He has struck the right balance between technical requirements and pragmatic and practical advice, based on his own extensive industry knowledge and experience. He seeks to bring the right team for the matter in hand.
Legal 500 UK 2023 - Data Protection, Privacy And Cybersecurity – Tier 2 - Simon Persoff and his team offer a breadth of practical experience as well as legal expertise.
Legal 500 UK 2023 - Data Protection, Privacy And Cybersecurity – Tier 2 - Simon Persoff is extremely responsive and provides clear, practical, commercially sensitive advice.
Legal 500 UK 2022 - Data Protection, Privacy and Cybersecurity – Tier 2
- Simon Persoff is a technical expert with a deep understanding of the GDPR and other data protection regulation.
Legal 500 UK 2022 - Data Protection, Privacy and Cybersecurity – Tier 2
- Simon Persoff is incredibly hard working and committed to giving clients a high quality service.
Legal 500 UK 2022 - Data Protection, Privacy and Cybersecurity – Tier 2