A part-time employment contract is a contract of employment under which an employee works fewer hours per week than a comparable full-time employee in the same or a similar role. Part-time work is one of the most common forms of flexible working in England and Wales, and it is used across virtually every sector of the economy. Parents returning from parental leave, students, carers, semi-retired professionals, and individuals who simply want a better work-life balance all frequently work part-time hours.

In England and Wales, the rights of part-time employees are protected by the Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000 (“the PTW Regulations”), which implemented the EU Part-Time Work Directive. The PTW Regulations remain in force following Brexit. Their central principle is straightforward: a part-time worker must not be treated less favourably than a comparable full-time worker simply because they work part-time, unless the difference in treatment is objectively justified.

The PTW Regulations apply to employees and also to some categories of worker who are not employees in the strict legal sense. Under regulation 1, a part-time worker is any worker who works fewer hours than a comparable full-time worker. A comparable full-time worker is one employed by the same employer, under the same or a broadly similar contract, and engaged in the same or broadly similar work, having regard to qualifications, skills and experience.

The equal treatment principle under the PTW Regulations covers pay, holiday entitlement, access to occupational pension schemes, sick pay, training and career development, access to promotion and permanent roles, and access to enhanced redundancy pay. Each of these entitlements must be provided on a pro-rata basis, meaning in proportion to the part-time worker’s hours as a fraction of the full-time equivalent. A part-time employee who works three days out of a five-day full-time week is therefore entitled to three-fifths (60%) of the full-time pay, 60% of the full-time annual leave entitlement, and so on.

The Employment Rights Act 1996 also applies in full to part-time employees. They are entitled to a written statement of employment particulars on or before their first day of work, and this statement must accurately record their contracted hours and working days. Part-time employees acquire the right to claim unfair dismissal after the same qualifying period of continuous employment as full-time employees. They are entitled to Statutory Sick Pay if they meet the qualifying conditions, and to Statutory Maternity, Paternity, Adoption, and Shared Parental Pay. They are protected from unlawful discrimination on grounds of sex, race, disability, religion, sexual orientation, age, and other protected characteristics under the Equality Act 2010. Requests by part-time employees to switch to full-time working or to different part-time hours are governed by the flexible working provisions of the Employment Rights Act 1996, as amended by the Employment Relations (Flexible Working) Act 2023.

A part-time employment contract is needed whenever you engage an employee on a regular basis for fewer hours per week than the full-time standard for that role. It is not a casual or as-needed arrangement — if the hours are regular and guaranteed each week, you need a proper part-time employment contract rather than a zero hours contract, regardless of the number of hours involved.

Common situations in which a part-time employment contract is required in England and Wales include the following. First, when a current full-time employee requests a change to part-time working — for example, following the birth of a child, to care for an elderly relative, or for health reasons. Under the Employment Relations (Flexible Working) Act 2023, employees have the right to make a flexible working request from day one of employment, and if such a request is granted, a new contract or written variation to the existing contract must be put in place. Second, when you are hiring someone who has specifically applied for a part-time role, either because you have a genuine part-time vacancy or because you want to fill a full-time role by job-sharing. Third, when you are increasing an existing part-time employee’s hours significantly enough that a new contract is appropriate to record the new arrangements clearly.

A part-time employment contract must state clearly and accurately the contracted hours and working days. Vague provisions such as “approximately 20 hours per week” create ambiguity about pro-rata entitlements and can lead to disputes. The contract should state the exact number of hours per week, the specific days on which the employee will work, and the start and finish times. If the employee’s hours are expected to vary from week to week, a zero hours contract or casual agreement may be more appropriate.

The pro-rata calculation of holiday entitlement requires particular care. The statutory minimum under the Working Time Regulations 1998 is 5.6 weeks per year. For a full-time employee working five days a week, this is 28 days. For a part-time employee working three days a week, this is 16.8 days. The contract should state the actual number of days or hours of leave the employee is entitled to, calculated by reference to the number of days or hours they work each week, and should clarify whether bank holidays are included within this entitlement or additional to it. Part-time employees who work different days to the days on which bank holidays fall may be entitled to a pro-rata equivalent in lieu of bank holidays they cannot take.

A legally compliant part-time employment contract for England and Wales must address several specific requirements arising from the PTW Regulations, the ERA, and other applicable legislation. Each of the following elements is essential.

The contracted hours clause is the most fundamental element of a part-time contract. It must specify the exact number of hours per week the employee is contracted to work, the specific days and the start and finish times. It should also state the full-time equivalent hours for the role. This information is the foundation for all pro-rata calculations throughout the contract and is required by section 1(4)(c) of the ERA.

The pro-rata entitlements clause confirms the equal treatment principle under the PTW Regulations. It should clearly state that all the employee’s entitlements under the contract, including pay, holiday, sick pay, and pension, are calculated on a pro-rata basis by reference to their contracted hours as a proportion of the full-time equivalent. This prevents any ambiguity about whether the employee is entitled to the same absolute amounts as a full-time employee.

The holiday entitlement clause must specify the actual number of days or hours of annual leave the employee is entitled to, calculated on a pro-rata basis. It should specify the holiday year, how holiday is accrued, the notice required to take holiday, and what happens to accrued untaken holiday at the end of the contract. The clause should also address the treatment of bank holidays on a pro-rata basis for employees who do not work on the days when bank holidays fall.

The pay clause must state the employee’s actual salary or hourly rate — the amount they will receive for their contracted part-time hours — and must confirm that this rate is at least the applicable National Minimum Wage or National Living Wage for their age under the National Minimum Wage Act 1998. The pay clause should also specify the pay frequency and the method of payment.

The flexible working clause is increasingly important. Since the Employment Relations (Flexible Working) Act 2023, employees have the right to make a flexible working request from day one of their employment, and employers are required to consult with the employee before refusing a request. The contract should acknowledge this right and direct the employee to the Employer’s flexible working policy.

The pension auto-enrolment provisions must comply with the Pensions Act 2008. Part-time employees are subject to the same auto-enrolment obligations as full-time employees. If the employee earns above the earnings trigger (£10,000 per year as of 2024/25), they must be automatically enrolled in a qualifying workplace pension scheme. Part-time employees who earn between £6,240 and £10,000 per year have the right to ask to be enrolled, and the employer must enrol them and make minimum contributions if they ask.

The notice period provisions must comply with the statutory minimums in section 86 of the ERA. Part-time employees have exactly the same statutory notice entitlements as full-time employees: one week after one month of employment, rising by one week for each complete year of service, up to a maximum of 12 weeks. The contract should specify a contractual notice period that is at least as long as the statutory minimum.

The equal treatment statement confirms the employer’s obligation under regulation 5 of the PTW Regulations. If the employer provides materially less favourable terms than those of a comparable full-time employee (other than on a pro-rata basis), the employer must be prepared to demonstrate an objective justification for that difference in treatment.