Part time hours & workers’ rights: HR guide

Understanding what counts as part time hours is important in determining the rights and entitlements of your part time workers.

Below we look at what is classed as part time hours and how – save except in limited circumstances – the law protects these workers from less favourable treatment than full time workers by reason of working part time.

What are part time hours?

There is no specific formula that will determine whether or not someone is working part time or full time hours, and no legal maximum or minimum number of hours before someone is considered a part time worker.

Under the Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000 (“the 2000 Regulations”) a person is classed as part time if they are not a full time worker based on the ‘custom and practice’ where they work. The 2000 Regulations provide that a worker is a part time worker:

“…if s/he is paid wholly or in part by reference to the time s/he works and, having regard to the custom and practice of the employer in relation to workers employed by the worker’s employer under the same type of contract, is not identifiable as a full-time worker”.

Essentially, this means that a part time worker is simply someone who works fewer contracted hours than a full time worker for that particular type of work within the workplace in question. In some companies or organisations, full time hours might be 30 hours and above over the course of one week, whereas in others, full-time hours might be 35 hours or more a week.

Even though a part time worker will undertake fewer contracted hours than a full time worker, they may still have the option to work overtime, if and when desired. As with many full time workers, part time workers generally also hold permanent positions, and their contract of employment should contain many of the same contractual provisions as their full time counterparts.

Job sharing and term-time working are both forms of part time working, where members of staff who work under such arrangements have the same rights as other part time workers. Many employers will often provide these types of flexible working arrangements to allow individuals to fit their work around other commitments, creating a better work/life balance for their staff.

What is the process for identifying a comparable full-time worker?

A comparable worker is defined as a full time worker who is employed by the same employer under the same type of contract as the part time worker, and is engaged in the same or broadly similar work.

When considering whether the work is similar, the level of qualifications, skills and experience necessary to undertake the job roles may be taken into account, although minor differences, especially where the work of the part time worker is of equal or greater value, should be disregarded.

In circumstances where a full time worker has reduced their hours to become a part time worker, that worker is entitled to compare their new part time terms and conditions with those s/he had when they worked on a full time basis.

What are part time workers’ rights and entitlements?

With limited exceptions, part time workers have the same rights and entitlements that full time workers get, albeit in an equal proportion to the number of hours that they work, ie; applying the pro rata principle where appropriate.

The pro rata principle means that where a comparable full time worker receives (or is entitled to receive) pay or any other benefit, a part time worker is to receive (or be entitled to receive) not less than the proportion of that pay or other benefit that the number of his or her weekly hours bears to the number of weekly hours of the full time worker doing the same work.

This means that if you employ a part time worker, in addition to any basic statutory entitlements, they should receive the pro rata equivalent to any comparable full time worker for any contractual entitlements provided by your company or organisation, including:

• Pay rates and bonuses
• Sick pay
• Annual leave
• Maternity, paternity and adoption leave and pay
• Training and career development
• Opportunities for career breaks
• Selection for promotion and transfer
• Selection for redundancy
• Occupational pension opportunities and benefits

It is important to remember that the protection afforded to part time workers includes anyone who works under a contract of employment, ie; employees, or any other contract for providing services personally, ie; workers such as zero hours contract workers, casual workers and agency staff.

Pay rates and bonuses

Part time workers have the legal right to equal pay for equal work. This means that they must be paid the same hourly rate or basic rate of pay as a comparable full time worker.

In the case of bonuses, the benefit may need to be applied pro rata, ie; in proportion to the number of hours undertaken by the part time worker. For example, if a full time worker is paid an annual bonus of £500, where a part time worker works only half the number of hours, they should be paid £250.

Selection for redundancy

In a redundancy situation, part time workers should be treated no less favourably than their full time equivalents. Different treatment of part and full time workers will only be lawful if it can be justified on objective grounds.

Sick pay

To comply with the law in relation to contractual sick pay, part time workers should not be treated less favourably than comparable full time workers in terms of calculating the rate of pay, the length of service required to qualify for any payment of contractual sick pay and the length of time the payment is received.

Annual leave

In cases where comparable full time workers have an enhanced contractual entitlement to annual leave, part time workers should have the same entitlement on a pro-rata basis. This means that if a part time worker undertakes 50% of the hours of their full-time colleague doing the same job, s/he will be entitled to the equivalent of 50% of their annual leave allocation.

Maternity, paternity and adoption leave and pay

As with contractual sick pay, part time workers should not be treated less favourably than comparable full time workers in terms of calculating the rate of maternity, paternity and adoption pay, the length of service needed to qualify for any such payment and the length of time the payment is received.

In relation to any enhanced contractual right to maternity, paternity and adoption leave, the right to take leave should be available to part time workers in the same way as for comparable full time workers.

Training and career development

Part time workers must not be excluded from training or opportunities for career development simply because they work on a part time basis. This means that, wherever possible, training will need to be scheduled to suit most members of staff, including part-time workers.

Opportunities for career breaks

Careers break schemes should be available to part time workers in the same way as for comparable full time workers, unless their exclusion is objectively justified on grounds other than their part time status.

Selection for promotion and transfer

Part time workers must not be excluded from promotion or transfer because they work on a part time basis, unless it can be justified objectively.

Occupational pension benefits

Both full time and part time workers should have equal access to any occupational pension schemes. This means that part time workers have the same rights to join any workplace pension scheme or to be automatically enrolled, provided that they are eligible for this.

Protections for part time workers from unfavourable treatment

The 2000 Regulations give part time workers the right in principle not to be treated less favourably than full time workers of the same employer who work under the same type of employment contract simply because they are part time.

However, there are some limited circumstances in which less favourable treatment can be justified on objective grounds. This means that the normal rules relating to part time workers can be broken where the reason for the difference in treatment is necessary to achieve a legitimate aim, and is the most appropriate way to meet a genuine business need.

An example of objective justification could include a part time worker who is denied health insurance, even though a comparable full time worker has this, because of the disproportionate cost to the business of providing the benefit.

It is worth noting that it will not be treated as less favourable treatment to pay a part time worker a lower rate of pay for any overtime worked beyond their normal hours, save except where they have exceeded the number of hours that the comparable full time worker is required to work to be entitled to any enhanced pay rate.

This means that you are entitled to set the same hours threshold for enhanced overtime pay as for full time workers, and only once this threshold has been reached will the part time worker become entitled to a higher pay rate.

What are the consequences of treating a part time worker less favourably?

If a part time worker is treated less favourably as regards the terms of his or her contract, or by being subjected to any other detriment within the workplace under the 2000 Regulations, they have a statutory right, on request, to a written statement of reasons for the treatment.

Having received a request, you must respond in writing within 21 days. If the worker is not satisfied that the reasons given for not treating them in the same way as a full time worker are objectively justified, they may be able to take a case to an employment tribunal. Any written statement provided by you can be taken into account by the tribunal hearing the complaint.

If it appears to the tribunal that you have deliberately, and without reasonable excuse, omitted to provide a written statement, or that the written statement is evasive or equivocal, it may draw an inference that the rights of the part time worker have been infringed.

Can you change an employee’s contracted hours from full to part time hours?

It is possible to change an employee’s contracted hours from full to part time, as long as this has been agreed with them.

In addition, a right is given to workers who become part time or, having been full time, return part time after absence, for example, following maternity leave, to not be treated less favourably than they were before going part time. In these circumstances, the worker would be entitled to compare their part time conditions with their previous full-time contract.

Part time hours & working FAQs

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Legal disclaimer

The matters contained in this article are intended to be for general information purposes only. This article does not constitute legal advice, nor is it a complete or authoritative statement of the law, and should not be treated as such. Whilst every effort is made to ensure that the information is correct, no warranty, express or implied, is given as to its accuracy and no liability is accepted for any error or omission. Before acting on any of the information contained herein, expert legal advice should be sought.