The Coalition Government made great play of its banning the use of exclusivity clauses in zero-hours contracts, ensuring that employees with no guaranteed hours are free to do work for other employers. We could debate how meaningful that restriction is, but a recent news story has identified a more fundamental problem with regulating zero-hours contracts. Santander is reported by the Financial Times as employing 371 ‘on-call customer services assistants’ – each with a guarantee of just one hour’s work every month. There is no evidence that the employer is doing this to avoid the ban on exclusivity clauses – they say that it is to allow for appropriate training – but the fact is that such an arrangement does mean that the employees are not classed as employed on zero-hours contracts. It goes to show that regulating ultra-flexible work is no easy task.