An estimated 315,000 unpaid carers aged 16 to 64 in England, predominantly women, have left full-time or part-time employment to provide care. n A key threshold at which carers in England are at risk of leaving employment occurs when care is provided for 10 or more hours a week, a lower threshold than previously thought. n The public expenditure costs of carers leaving employment are estimated at £1.3 billion a year, based on the costs of Carers Allowance and lost tax revenues on foregone incomes alone. n Access to publicly-funded services by working carers is low, with only 4% of carers working full-time, and 6% working part-time, currently offered an assessment or review. n There is little evidence that councils systematically use services for the cared-for person as a means of supporting carers whose employment is at risk. n Councils target their support at people providing care for 35 hours a week or more and are therefore not in contact with large numbers of carers whose employment is at risk. n Despite an increasing emphasis in government policy on ‘replacement care’, the study has not found any scientific papers on the effectiveness of services for the cared-for person (‘replacement care’) as a means of supporting working carers in England. n There is a need for further evidence to support the development of policies around ‘replacement care’ for working carers in England.