Over the past 25 years, marriage rates have plummeted in the UK. The age at first marriage rose dramatically, and cohabitation is now the normative way of entering the first coresidential partnership. Simultaneously, youth precariousness has increased in the labour market, dominated by low wages, fixed-term contracts and unemployment. The question arises whether couples’ economic precariousness has contributed to the decline in marriage, and if so, whether there are differences by gender, education and historical periods. Using cohabiting couple dyads, we explore the relationship between young couples’ economic precariousness and the likelihood of marriage and partnership dissolution between 1991 and 2018. Findings show that cohabiting couples without precarious partners are most likely to marry and those with one precarious partner, especially male, present lower risk of marriage and higher one of dissolution. However, there are differences between subjective and objective indicators. We also find gradients by education and historical period.