PurposeThis paper uses the Social Identity Model of Collective Action (SIMCA) framework of Zomeren et al. (2008) to explain the organising experiences of the informal sector workers engaged in large number in the world's largest shipbreaking industry located in the western Indian town of Alang.Design/methodology/approachA single case study approach was adopted to understand the participation of shipbreaking workers in their trade union and factors that influence their participation.FindingsSense of cohesive collective identity and injustice alongside efficacy considerations have shaped the organising experiences and affected the participation of informal sector workers in their union. The trade union was able to overcome the scourge of invisibility that has been one of the dominant features of informal sector employment.Research limitations/implicationsThis paper treated union participation as unidimensional. Besides, the subjective conceptualization of strengths of perceptions of injustice, identities and efficacy considerations could be a limitation. The paper does acknowledge the gendered nature of shipbreaking but have not actively pursued it as a part of our research.Practical implicationsThe findings of our study are an exemplar for those who intend to organise informal sector workers, especially precarious workers. The empirical findings allude to the role of trade unions in combating the invisibility, which is one of the defining features of informal sector workers through a distinctive, cohesive identity inculcated in those workers.Originality/valueThis paper has borrowed the SIMCA framework to explore union participation. Organising experiences of precarious workers from the developing world provides a contextual and an empirical novelty to our study.