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Working time, rest & on-call - a reminder of employer's duties

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Working time, rest & on-call - a reminder of employers duties

There are lots of good reasons for employers to remind themselves of the rules around maximum limits on working time, required rest breaks and the interplay of these with workers who perform on call work:

  • With hybrid working being the rising trend, one of the issues that employers need to consider is whether, for some, it might lead to a worse work/life balance as employees blur the lines between work and home
  • We’re seeing more businesses diversifying and requiring, for one reason or another, unsociable hours working in order to service their client base or keep their operations running smoothly
  • Although derived from EU law, our rules around working time are enshrined in UK law and continue to apply despite the UK having left the EU


The Working Time Regulations 1998 (WTR) were introduced to regulate the number of hours workers perform, and the ways in which rest periods and holidays work. 

It’s important that employers note that the factors which determine working time for the purposes of the WTR are not necessarily the same as those which determine working time for the purposes of National Minimum Wage. In other words, just because a period of working time is required to be paid under the National Minimum Wage Regulations, that does not automatically mean it will be working time for the purposes of the WTR. This article examines WTR issues only.

Key issues

Key principles under the WTR include:

Workers’ weekly working time

Workers’ weekly working time must not exceed 48 hours per week on average. This average is calculated over 17 weeks. 

  • A worker may sign an opt-out of the maximum 48-hour working week. However, they can’t be forced to opt-out or subjected to victimisation for not opting-out and, even if they do opt-out, they can cancel this on 7 days’ notice (or up to three months’ notice if the opt-out agreement provides for that).


Rest-periods are a key responsibility of the employer to allow workers to take. As a starting point, the WTR generally allows workers the following: 

  • Daily rest period of 11 hours uninterrupted rest per day
  • Weekly rest of 24 hours uninterrupted rest per week, or 48 hours per fortnight (which of the two is at the discretion of the employer).
  • 20 minute break when working more than 6 hours in a day.

Further key points around rest periods are: 

  • Employers need to actively encourage the taking of breaks. This means creating an atmosphere were breaks are a scheduled part of the working day.
  • Workers mustn’t feel under pressure to not take a break. That doesn’t just mean direct pressure – this can include being made to feel as though they shouldn’t take a break because their colleagues don’t and they feel under pressure to follow suit.  
  • Workers carrying out monotonous work, e.g. on a production line, attract special protection. They may need to be given more regular, short breaks, in addition to the above standard breaks. 
  • Workers must, wherever possible, be given compensatory rest if they’ve had to work through a rest period. This might happen, for example, with a shift worker changing from day to night work.
  • Employers must keep and maintain records around average working time and night work demonstrating that the rules are being complied with.


On-call – or stand-by is time spent by workers where they aren’t necessarily always actively performing work, but they are required by the employer to be available and can be called upon to perform work if required. On call work has been the subject of a great deal of debate and case law. 

Determining whether shifts spent on call are working time for the purposes of the WTR are important for workers who also carry out other, set working patterns, as it can impact whether they are being afforded sufficient rest.

In broad terms, the current position under the WTR in relation to being on call is that:

  • Time spent on-call or on standby at a location specified by the employer is all likely to be working time, regardless of how much time the worker spends actively carrying out work, and even if the chance of being called upon to perform duties is low. This also applies even if the employer gives a little bit of freedom, but still requires the worker to be within, for example, a few miles of their normal place of work.
  • Even if the employer doesn’t set rules around where the worker needs to be, but they impose other constraints which objectively have a very significant impact on the worker’s opportunity to pursue personal and social interests, it’s likely that all of the on call time will be working time. 
  • The WTR only distinguishes between working time and rest time. In practice, many workers on call aren’t actually carrying out work, but can’t pursue their own activities either in case they’re called on to work. Factors which will help determine whether on call time is working time include:
    • Any constraints imposed on a worker that objectively and very significantly affect their ability to freely manage the time during which their services are not required and use that time as they want. The more constrained they are, the more likely it is that merely being on call will be considered working time
    • Conversely, when there are no such constraints, only the time when work is actually carried out will constitute working time 
    • In principle, if a worker on call is able to plan personal and social activities, and carry out any required work around this, this does not constitute working time. On the other hand, if an on call worker is required to return to work within a few minutes then the whole period of being on call will be considered working time. The requirement to resume work quickly makes it very difficult for the worker to plan any kind of recreational activity, even something short.

Tips for reducing the risk that all on call time (even when no work is performed) is considered working time:

  • Don’t require the worker to be at any particular location (whether that is a workplace or their home) – for example, make clear they can be anywhere as long as they have their phone/laptop available
  • If certain response times are required, have these as long as possible. The shorter the response time, the greater the risk all on call time will be considered working time. Cases have determined that 3 and 10 minute response times rendered all on call time to be working time
  • Don’t require the worker to have to attend the workplace when called – or, if they may need to, limit this as much as possible and have a lengthy response time. Also, don’t require them to wear anything in particular, e.g. a uniform, which might restrict them further
  • The greater the number of calls the worker will need to respond to, the higher the chance that all of their on call time will be considered working time (as they won’t have sufficient time between calls to realistically pursue leisure activities)
    • If the worker is able to choose to accept/reject a % of calls that will help minimise the risk of all time being on call time. This is more relevant where, for example, a number of workers are on call at the same time and if one rejects a call it bounces to another.