Purpose: Migration waves have a significant impact on cultural diversity. But in various sections of the economy the authors observe large numbers of unregistered workers. The purpose of this paper is to map out the socio-economic situation of unregistered migrant workers and aims to identify the drivers of their labour market position in terms of job opportunities and salary. The specific focus of this study will be on undocumented immigrant workers involved in the domestic work (or household) sector in the Netherlands. Design/methodology/approach: This paper offers empirical evidence on two levels: the individual level (migrant domestic workers), and the household level (from an employer perspective). Findings: The paper finds that years of work experience and social network participation - in particular, family relationships and a combination of friends with employer relationships - increases the chances of finding a higher paid irregular job. From a household perspective, there appears to be a positive relationship between both the age of the employer and the size of the household on the one hand and the hours of domestic work needed per week on the other hand. Clearly, demographic change towards an ageing population will increase the demand for undocumented domestic workers. Practical implications: Reliable data on undocumented immigrants living and working in developed economies are rare. This also holds true for the Netherlands. For labour unions, this is a neglected category of workers and hence it is important to investigate their job conditions. Originality/value: The Netherlands is becoming an ageing society and this is a factor that increases the demand for irregular domestic work. This paper explores the role of ageing and labour market participation on household demand for irregular domestic work. Furthermore, the paper analyses the impact of social capital dimensions on access to a better-paid illegal job for undocumented migrant domestic workers in the Netherlands. © Emerald Group Publishing Limited.