Part-time contracts: key features and legal requirements

A part-time contract is an employment agreement where an employee works fewer hours than a full-time worker in the same organisation. The standard full-time working week in the UK is typically 35 to 40 hours, usually spread over five days (Monday to Friday), with shifts lasting around eight hours. Research suggests that the typical part-time contract employee works about 16.7 hours a week.

In today’s evolving job market, where dual-income households, side gigs, and second jobs are increasingly common, part-time contracts have become more crucial than ever. They provide both workers and employers with greater flexibility, improved work-life balance, and enhanced overall engagement and productivity.

Fixed hours vs. variable hours part-time contracts

Part-time contracts can be structured in two main ways: fixed hours and variable hours. While both involve fewer hours than a full-time contract, they differ significantly in terms of schedule predictability and flexibility.

Fixed hours part-time contract

A fixed hours part-time contract guarantees a set number of working hours per week or month. Employees follow a regular schedule, such as Monday to Wednesday from 9 AM to 1 PM or 12 hours per week.

A key element of a fixed hours contract is the mutuality of obligation: the employer is required to provide the agreed-upon hours, and the employee is obligated to work those hours. This makes it ideal for consistent, ongoing roles, such as retail assistants, office administrators, or healthcare workers.

Variable hours part-time contract

A variable hour’s part-time contract (sometimes referred to as a zero-hours contract) does not have a fixed schedule. Instead, the number of hours worked can change week by week depending on business needs.

Unlike fixed hours contracts, variable hours agreements do not include mutuality of obligation; meaning employers are not required to offer work, and employees are not required to accept it. This arrangement suits industries with fluctuating demand, such as hospitality, event staffing, and seasonal retail work.

Choosing between fixed and variable hours part-time contracts

A fixed hours part-time contract is best for roles requiring regular, predictable working hours. This provides employees with job stability and a consistent income, while allowing employers to maintain a steady workforce. It is most suitable for jobs with ongoing, stable workloads, such as administrative roles or retail shifts.

Conversely, a variable hours part-time contract is better for businesses with fluctuating demand. It allows employers to scale staffing levels up or down as needed, making it an ideal choice for hospitality, events, and seasonal work. However, employees in these roles must be comfortable with potential income variations and irregular schedules or else it can lead to staff engagement issues.

Part-time workers’ rights

Historically, part-time workers have at times faced discrimination compared to their full-time counterparts. To address this, UK law now prohibits treating part-time employees less favourably simply due to their part-time status.

Under the law, part-time workers must receive equal treatment in key areas, including:

• Pay rates (including sick pay, maternity/paternity/adoption leave and pay)
• Pension contributions
• Holidays and paid time off
• Access to training and career development
• Eligibility for promotion, transfer, and redundancy protection
• Opportunities for career breaks

When employers can treat part-time workers differently

In some cases, employers may be allowed to treat part-time workers differently if they can provide a valid objective justification. This means they must prove that different treatment is necessary and proportionate for a legitimate business reason.

For example, the government has cited health insurance as a possible justification. If providing full health insurance to part-time workers would be disproportionately expensive compared to their working hours, an employer may require part-time employees to contribute toward the cost.

Risks of unfavourable treatment of part-time workers

Employers should take great care when drafting part-time contracts and setting benefits policies. If a part-time worker believes they are being treated unfairly, they have the legal right to challenge their employer.

The process for resolving disputes includes:

1. Requesting a written statement from the employer explaining the reasons for their treatment. Employers must respond within 30 days.
2. If the worker is unsatisfied with the response, they may file a complaint with an employment tribunal.

Employers who fail to justify differential treatment risk legal consequences, including compensation claims and reputational damage.

Part-time contracts play a crucial role in the modern workforce, offering flexibility for businesses and work-life balance for employees. Whether using fixed hours contracts for stable roles or variable hours contracts for fluctuating demands, employers must ensure they comply with legal protections for part-time workers.