This Practice Note examines the provisions of the Employment Rights Act 1996 (ERA 1996) in relation to continuity of employment. It sets out the purposes for which continuity of employment (length of service) is important (ie the right to bring claims and level of compensation), general principles of calculation, when the continuous employment period starts and ends, breaks in continuity (break in service), how the period of continuous employment is calculated, when continuity is not broken by a change in employer, weeks which count when there is a contract of employment, weeks which count when there is no contract of employment, the effect of sickness, injury or a temporary cessation of work, when there is an arrangement or custom preserving continuity, the effect of zero hours contracts, rules in relation to health service employers, the protection of redundancy payments for NHS and public authority employees, and the effect of illegality, and when a statutory redundancy payment breaks continuity. It also covers continuity rules in relation to overseas employment and redundancy, reinstatement after military service (military reservist) and