Models of cooperative and non-cooperative behaviour opened the household “black box” and allowed for individual treatment of partners in couples. However, labour supply literature has so far largely ignored a broader issue – the distinction of single versus multi-family (“complex”) households. We propose a method to account for multi-family household structure by borrowing from recent applications of the collective model to identify the degree of sharing. We assume that each household is characterised by a between-family sharing parameter, which is calibrated on estimated preferences, observed labour market status and other characteristics. We apply the method to Polish labour market data.