A zero-hour contract is an arrangement between a worker and an employer where the employer has no obligation to guarantee a minimum of working hours and the worker is not obliged to accept the working hours offered. While zero-hour contracts may be suitable in some cases, such as to cover seasonal peaks and to enable students to work over vacation periods, they are generally unsuitable to run a core business, especially in cases where the patterns of work can be reasonably predicted, as for example shop opening hours. The incidences of low-paid zero-hour contracts have been reported across the fashion supply chain, especially in retail. In most cases, rather than offering workers the advantage of flexibility, zero-hour contracts can become a form of modern slavery, where employees work for low pay, with insecure and often last-minute working patterns, which makes them vulnerable to exploitation.