Night working hours

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1. Hours and limits

Staff who regularly work at least 3 hours during the ‘night period’ are night workers.

The night period is 11pm to 6am, unless the worker and employer agree a different night period.

If they do, it must be 7 hours long and include midnight to 5am. It must be agreed in writing.

Staff may also be night workers if there’s a collective agreement (for example, trade union agreement) that states their work is night work.

National Minimum Wage

The National Minimum Wage applies to night workers but there is not a higher night working rate.

Sleep-in shifts

The number of hours that workers get paid the National Minimum Wage depends on whether they’re expected to sleep or work for most of their shift.

Workers who are expected to sleep for most of a sleep-in shift (for example, a care worker), and are provided with suitable sleeping facilities, will only get the National Minimum Wage for the periods when they’re awake to perform tasks.

Workers who are expected to work for most of a shift will get the National Minimum Wage for their whole shift, even if they’re allowed to sleep between tasks.

Limits on working hours for night workers

Additional rules apply to night workers on top of the rules on maximum weekly working hours and rest breaks.

Night workers must not work more than an average of 8 hours in a 24-hour period.

The average is usually calculated over 17 weeks, but it can be over a longer period of up to 52 weeks if the workers and the employer agree - for example, by collective agreement.

Regular overtime is included in the average, but not occasional overtime.

Workers cannot opt out of the limit.

Workers aged 16 or 17

Staff aged 16 or 17 cannot work between midnight and 4am.

They usually cannot work between 10pm and 6am (this can be changed to not working between 11pm and 7am, by contract) but there are exceptions if they work in:

  • agriculture
  • cultural, sporting, artistic or advertising activities
  • a hospital
  • a hotel or catering
  • retail
  • post or newspaper delivery

In exceptional circumstances they can work at night if there’s no adult to do the work and they’re needed to either:

  • handle a sudden increase in demand
  • maintain the continuity of a service or production - for example, filming

The employer must give the young person a rest period of the same length as the extended shift.

There are other restrictions on employing young people.

Special hazards and mental or physical strain

Night workers who deal with special hazards or whose work involves mental or physical strain cannot work longer than 8 hours in any 24-hour period.

A risk assessment must be carried out to identify special hazards and work involving mental or physical strain.

The hazards and strains may also be set out in collective or workforce agreements.

What employers must do

Employers must keep records of night workers’ working hours to show they are not exceeding the limits.

The records must be kept for at least 2 years.

Contact Acas for more information.

You cannot discriminate against a worker if they do not want to work nights.

2. Exceptions to night work limits

The limits on night working hours do not usually apply:

  • in the armed forces and emergency services
  • to domestic staff employed in a private house
  • when people can choose how long they work - for example, company executives or freelancers

The limits on night working hours do not apply:

  • in jobs that need round-the-clock staffing, like hospital work
  • in an industry with busy peak periods, like agriculture, retail, tourism, security and surveillance
  • if there’s an emergency or an accident
  • if a member of staff has to travel a long distance from home to work or constantly works in different places
  • if a collective or workforce agreement excludes or changes the restriction on night work

Different rules apply to workers in road, sea and air transport.

Rest breaks if night work limits do not apply

Workers must get ‘compensatory rest’ instead of a normal working week with breaks during the day.

Compensatory rest is a minimum of 90 hours rest per week on average.

Employers must also follow the general rules on working hours.

If you’re not sure whether these exceptions apply in your situation, contact Acas.

3. Health assessments

Employers must offer workers a free health assessment before they become a night worker. Workers do not have to accept.

The assessment must be written by a qualified health professional. It can be a questionnaire.

Employers must take into account that night work might increase a worker’s stress levels.

The worker must get a follow-up examination by a health professional when an employer is unsure if the worker is fit for night work.

A repeat assessment must be offered regularly.

The employer must offer suitable other work where possible if a worker has health problems that a doctor says are related to night work.

Keep records

Employers must keep confidential records of:

  • the health assessments (keep for 2 years)
  • dates when assessments were offered (if a worker did not want one)