Profile information Account settings
Logout
Sign up Log in

Part-time workers

Part-time working is on the rise and it's an option that can suit both employers and staff who are seeking flexible working arrangements. The law on part-time working isn't complex but there are some points which need to be considered.

Last reviewed 14 October 2022.

Make your Employment contract
Get started
Answer a few questions. We'll take care of the rest

There is no specific number of hours that makes one worker part-time and another full-time. A part-time worker legally just means any worker who works less than the normal full-time hours in that workplace. While there is no set number of hours someone has to work to be considered full- or part-time, full-time workers usually work at least 35 hours per week.

The rules apply to 'workers' which covers some consultants and contractors, as well as employees. For more information on the differences between workers, employees and consultants, read Consultants, workers and employees.

Under the Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000, part-time workers have specific legal protections prohibiting less favourable treatment as compared to full-time workers. This particularly impacts:

Part-time workers are statistically more likely to be female than male. So, treating part-time workers less favourably may also be indirect sex discrimination under the Equality Act 2010. This is where a working practice applies to the whole workforce but one person (or group) is put at a disadvantage because of their sex. For more information, read Equal opportunities and discrimination.

Pay and leave benefits are calculated on a pro-rata basis. Pro-rata means in proportion to the hours worked. This means that part-time workers should receive a pro-rated proportion of pay and benefits received by a comparable full-time worker, according to the proportion of full-time hours they work. These terms should be written into their Employment contract.

A comparable full-time worker is someone who: 

  • works for the same employer and at the same place (where no comparable full-time worker works at the same place, at a different place) 

  • works under the same type of contract (eg not some working under an apprenticeship agreement)

  • is paid fully or partially by reference to the time they work

  • performs the same or similar work, and

  • has similar levels of skills, qualifications and experience

Holiday entitlement should be pro-rated but it is permissible to only give bank holidays that fall on the normal days of work of a part-time staff member.

For pay, it is generally a straightforward exercise to pro-rate the entitlements.

However, some benefits cannot readily be pro-rated, such as a company car, insurance benefits or gym memberships and employers sometimes simply withhold these benefits from part-time staff. For benefits that are withheld from part-time workers, the employer will have to show that this is objectively justified. To be an objective justification the reason for the different treatment must be:

  • necessary to achieve a legitimate aim or business objective, and

  • a necessary and appropriate way to achieve this objective

This may require showing that less discriminatory alternatives were considered but were not practicable (eg because the costs involved were disproportionate). One route to consider is providing a pro-rated cash equivalent of the benefit. 

Any part-time workers who believe they are treated less favourably than full-time workers should speak to their employer or trade union representative. Doing this can help resolve any issues without the need for a formal process.

Part-time workers are also entitled to a written statement of reasons for any treatment that is less favourable than that of full-time workers. Requests for a statement of reason should be made in writing and employers must provide the statement within 21 days of the request being made. 

Where the employer fails to provide a justifiable reason or the worker is not satisfied that the reason given was objectively justified, they may be able to bring a case to an Employment Tribunal.

Sometimes part-time workers are viewed as less committed staff members or not taken seriously in the workplace because of their part-time status. This is unlawful and part-time workers should be given the same access to training, promotion and other opportunities as full-time workers.

Bear in mind that a request to work part-time may qualify as a statutory flexible working request requiring a formal process and response. It’s worth having a Flexible working policy in place to ensure that rights are upheld and obligations are met. For more information, read Flexible working. Even if it does not qualify as a flexible working request, there may be issues of sex discrimination to look out for.

Employers may offer overtime pay to staff who work more hours than the employment contract says. Under the law, part-time workers are not entitled to overtime pay unless they have worked more than the hours normally worked by a full-time worker. However, employers may have a different overtime policy (eg allowing part-time workers to receive overtime pay if they work more than their normal hours). As a result, employers should check their internal policies and relevant employment contract before offering (or refusing to offer) overtime and overtime pay to part-time workers.

Employees should not be selected for redundancy on the basis that they are part-time and care should be taken to ensure that the selection criteria are adjusted so that they are fair to part-time staff.
If you have any questions about part-time workers and their rights, Ask a lawyer.

Make your Employment contract
Get started
Answer a few questions. We'll take care of the rest