Working hours: What you need to know

by Amber Rolfe

The secret’s out; working 9 to 5 isn’t the only way to make a living…

From flexible shifts to annualised hours, the modern workplace is a lot more fluid than it used to be. But while flexibility is great, you need to make sure you aren’t working more than you should be. Luckily, employers are legally obligated to ensure their employees aren’t working more than the allowed maximum amount. This legislation is there to protect you from being overworked and underpaid.

To ensure you’re working within your rights (and to answer any questions you have), here’s everything you need to know about working hours:

What are working hours?

Legally speaking, ‘working hours’ refers to the time when you are at your employer’s disposal and carrying out your duties.

This doesn’t just mean the time you spend sitting at a desk. Depending on your job, it can also include job-related training, time spent travelling (if it’s part of your role, like a Sales Rep), and working lunches.

However, it generally doesn’t include your commute to a fixed workplace, rest breaks where no work is done, or voluntary unpaid overtime.

What are the maximum weekly working hours?

Under the Working Time Regulations, you’re legally allowed to work a maximum of 48 hours a week.

However, this isn’t calculated on a single week-by-week basis. It’s an average hour work week calculated over a ‘reference period’, which is usually 17 weeks. This means you could work 55 hours one week and 40 the next, as long as the average doesn’t exceed 48.

If you’re under 18, the rules are stricter. You can’t usually work more than 8 hours a day or 40 hours a week.

Will I ever have to work more than the maximum?

In certain industries, the 48-hour limit might not apply, or the reference period might be longer (up to 52 weeks).

These exceptions often include:

• The armed forces, police, or emergency services
• Industries where 24-hour staffing is needed (e.g. healthcare)
• Security or surveillance
• Seafaring or sea-fishing
• If you’re self-employed and in control of your own hours

Opting out of the 48-hour week

If you want to work more than the 48-hour average, you can choose to ‘opt out’.

This has to be voluntary and must be done in writing. You can opt out for a specific period or indefinitely. Crucially, you can’t be fired or treated unfairly for refusing to sign an opt-out agreement. And if you change your mind later? You can cancel your opt-out agreement, usually by giving at least seven days’ notice (though your contract might require up to three months).

However, you can’t opt out if you work in certain safety-critical roles, like airline staff or drivers of certain vehicles.

Why does employment law exist?

Calculating hours worked

Need to figure out your average? It’s simpler than it sounds. Here’s how to do it:

• Add up the total number of hours you’ve worked over your reference period (usually 17 weeks)
• Divide that by the number of weeks.

Remember to include paid overtime and any unpaid overtime you were asked to do. Do not include paid holidays, sick leave, or lunch breaks.

Example: Let’s say you worked 680 hours over 17 weeks. To find your average weekly hours, just divide 680 by 17. That’s 40 hours per week on average.

What is included in my working hours?

• Time spent travelling, if travelling is part of your job (e.g. mobile therapist)
• Job related training
• Business lunches
• Time spent on call, on-site
• Time spent working abroad
• Time spent on business calls
• Paid overtime
• Unpaid overtime (which you’ve been asked to do)
• Travel between home and work for those who don’t have a fixed workplace (e.g. freelancers, contractors etc.)

What is not included in my average weekly working hours?

• Time spent on call, outside of the workplace
• Holidays (paid or unpaid)
• Breaks when work is not done (lunch breaks)
• Unpaid voluntary overtime
• Travelling outside of working hours
• Travel to and from work if you have a fixed workplace

Legal breaks at work

If you are aged 18 or over and work for more than six hours a day, you are entitled to an uninterrupted rest break of at least 20 minutes (although employers often extend this to 30 minutes or an hour). This is often your legal lunch break, though it can be taken for other reasons.

Technically, your employer can dictate when you take this break (as long as it’s not right at the start or end of the shift), but they can’t deny you taking it.

For employee breaks regarding workers under 18, the rules are more generous: a 30-minute break is required if working more than 4.5 hours.

You are also entitled to:

• Daily rest: You’re entitled to a minimum of 11 hours’ rest between finishing work one day and starting again the next.
• Weekly rest: Each week, you should get at least 24 hours of uninterrupted rest. Alternatively, your employer can give you 48 hours every two weeks.
• Annual leave: You’re entitled to at least 5.6 weeks’ paid holiday per year, based on your standard working week. For part-time workers, this is calculated pro-rata – so you still get a break, just in line with your hours.
• Bank holidays: These may or may not be included in your annual leave allowance – it depends on what your contract says.

Remember: Paid holidays, sick leave, and the rest of your time-off rights all link back to your basic working hours. If you’re unsure about what applies to you, check your employment contract or staff handbook for the details.

Contract of employment – key terms explained and your rights

Different types of working patterns

Not everyone works a standard week. Here is a breakdown of common patterns and what they mean for your hours.

Full-time and part-time

There is no specific legal definition for what are full time hours. However, a standard full time hours contract usually ranges between 35 and 40 hours a week.

Part time working generally means working fewer hours than a full-time employee at the same company. There are no minimum hours for part time set in law, so it could be anything from 4 hours to 30 hours a week.

Full-time hours vs part-time hours: what you need to know

Annualised hours

Annualised hours is where your working time is calculated over a whole year rather than a week. You’ll have a set number of hours to work annually, and your salary is paid in equal monthly instalments regardless of whether you worked 20 hours or 50 hours that month.

This is common in industries with seasonal peaks (like tourism or manufacturing). It offers stability in pay, even if the average hours of work per week fluctuate wildly.

Zero-hour contracts

Zero hour contracts are casual contracts where the employer is not obliged to provide any minimum working hours, and you are not obliged to accept any work offered.

While flexible, these contracts still afford you statutory rights, including the National Minimum Wage and paid annual leave (which is often calculated at 12.07% of hours worked for irregular hours workers).

Types of employment contracts

Overtime and time off in lieu

What is overtime pay?

Overtime pay is the additional pay you might receive for working beyond your contracted hours. In the UK, there’s no legal requirement for employers to pay extra for overtime, as long as your average pay for the total hours worked doesn’t fall below the National Minimum Wage. 

However, many employers choose to offer overtime pay as an incentive, sometimes at a higher rate than your normal hourly wage.

What is time and a half pay?

Time and a half pay means you’ll earn 1.5 times your usual hourly rate for each hour of qualifying overtime you work. For example, if your standard hourly rate is £10, time and a half bumps that up to £15 for every overtime hour.

Some companies also offer double time, which is twice your normal hourly rate. But, neither of these are required by law – they’re contractual benefits. This means whether you get them depends on your employer’s policy or what’s set out in your contract, so always check the details to avoid any surprises.

What is time off in lieu (TOIL)?

Instead of extra cash, some companies offer time off in lieu.

Time off in lieu means trading extra hours worked for holiday time. For example, if you work a Saturday, you might get a day off in the week to make up for it. This should be agreed upon in writing or outlined in your contract.

Employee benefits: What you need to know

Frequently asked questions

Can I request flexible working hours?

Yes. You can now request flexible working from day one of your employment. Put your request in writing, explain how it can benefit both you and the business, and outline how it could work in practice. 

Do I get paid for my lunch break?

Usually, no. Unless your contract states otherwise, the legal lunch break (the 20-minute rest break) is unpaid.

What are the hours for part time work?

There is no fixed number. Hours for part time are simply anything less than the standard full-time hours for that specific business.

What if I’m unhappy with my working hours?

The best first step is to talk to your manager. If you feel you are working more than the legal maximum or not happy with your working hours and breaks, you can raise a formal grievance. If that fails, you may need to contact ACAS or look into an employment tribunal.

Ready for a role with better hours? Have a look at all of our current vacancies now.

All information was correct at time of writing. Please visit https://www.gov.uk/maximum-weekly-working-hours for the most up-to-date information.