The conflict rules of European social security coordination in a digital labour market – bridging <i>lex loci laboris</i> and remote work by disregarding marginal cross-border activities

The article explores the complexities of determining the social security legislation applicable to employees engaged in cross-border remote work under Title II of Regulation (EC) 883/2004. Using remote work as a case study, it analyses the systematic interplay of various conflict rules. Social security legislation is traditionally tied to the physical location of employment ( lex loci laboris ), but the rise of remote work disrupts this paradigm, potentially causing frequent shifts in applicable legislation whenever employees work from different Member States. This ‘ping-pong effect’ may undermine legal certainty, impose administrative burdens and jeopardise workers’ social security rights. The article critically evaluates the EU Administrative Commission's Guidance Note on telework, which promotes a flexible interpretation of exceptions under Articles 12, 13 and 16 of Regulation (EC) 883/2004. While these exceptions help to resolve some difficulties, the author argues that the Administrative Commission fails to address the fundamental issue: at what point does cross-border remote work trigger a change in jurisdiction under the main rule in Article 11(3)(a)? The findings suggest that marginal activities – defined as constituting less than 5% of total working time and/or remuneration – should be disregarded within simultaneous and alternating working patterns under lex loci laboris . Such an approach allows the ‘usual’ State of employment to retain jurisdiction, thereby ensuring continuous affiliation for workers. Exclusion of de minimis activities is presented as a proportionate outcome, supported by the fundamental freedoms of free movement in primary EU law.