The promise and pitfalls of the Second Protocol to the Budapest Convention: Assessing its impact on EU and UK cross-border criminal investigations

This article provides a doctrinal and policy-oriented analysis of the Second Additional Protocol to the Budapest Convention, with a particular focus on its mechanisms for law enforcement access to non-content communications data in non-emergency situations. It interrogates whether the Second Protocol addresses the persistent legal and practical barriers faced by law enforcement agencies in accessing electronic evidence stored overseas. Through a close examination of the Second Protocol’s substantive provisions and their anticipated implementation in the UK and EU member states, the article argues that the Second Protocol is unlikely to achieve its stated objectives. While it formalises elements of voluntary cooperation and introduces safeguards intended to protect fundamental rights, its utility is constrained by legal fragmentation, potential conflicts with domestic data protection frameworks and the lack of robust enforcement mechanisms. Moreover, the article contends that the Second Protocol may, in some instances, complicate existing informal data-sharing practices unless domestic legal frameworks – particularly in the United Kingdom – are aligned with its requirements. Persistent uncertainty regarding the Second Protocol’s compatibility with the EU General Data Protection Regulation and the UK’s data protection regime further undermines its effectiveness. Ultimately, the article concludes that although the Second Protocol marks a significant step in multilateral cooperation in criminal matters, it does not obviate the continued need for bilateral frameworks. Substantial challenges remain in achieving a harmonised, rights-compliant and effective regime for cross-border access to electronic evidence.