Purpose - It is now widely recognised that in most economies there is a large number of hidden entrepreneurs operating wholly or partially "off-the-books". Until now, however, there has been a degree of silence on the gendering of such entrepreneurship, including exploring whether men and women have different motives for participating in hidden/informal entrepreneurship. The purpose of this paper, therefore, is to begin to fill this gap in the knowledge. Design/methodology/approach - The findings of face-to-face structured interviews with 130 informal entrepreneurs in England are reported; 70 are early-stage entrepreneurs and 60 are established business owner-managers, living in a range of affluent and deprived urban and rural English localities. Findings - A key finding of the paper is that three-quarters of entrepreneurs operate in the informal economy, with women informal entrepreneurs chiefly necessity-driven and men being largely voluntary participants in informal entrepreneurship. Further unpacking their motives, however, reveals not only that both necessity and choice are co-present motives for most informal entrepreneurs, but also that their motives change over time, with many women who originally entered informal entrepreneurship out of necessity becoming more opportunity-driven. Research limitations/implications - Although this survey is conducted in a diverse range of English localities to avoid the pitfall of generalizing from a specific locality-type, it does not provide nationally representative data on informal entrepreneurship. Originality/value - This is one of the first studies attempting to investigate why men and women engage in informal entrepreneurship.