Full-Time vs Part-Time Work in the UK: Definitions, Rights, and Practical Examples

In the UK, employment contracts often describe roles as either full-time or part-time, but what do these terms actually mean in practice? While the law sets certain limits around maximum working hours, there is no single legal definition of full-time or part-time work. Instead, the distinction is shaped by custom, contracts, and the protections that ensure part-time workers are treated fairly.

What does full-time mean in the UK?

There is no fixed legal number of hours that counts as full-time. However, most employers define full-time work as between 35 and 37.5 hours per week. Some contracts use 40 hours as a benchmark, but the most common range is 35–37.5.

Legally, the Working Time Regulations state that employees should not work more than an average of 48 hours per week unless they choose to opt out of this limit.

For payroll and workforce planning, this distinction is crucial because it determines how many hours and days employees are expected to work in a year. If you’d like a deeper look into how working days are calculated in the UK, see our guide on Working Days in the UK: Time Regulations and Practical Examples

What counts as part-time work?

Part-time work is any arrangement where an employee works fewer hours than a full-time schedule. This could mean working two, three, or four days per week, or shorter daily shifts across the week.

Part-time employees receive the same rights as full-time staff, but their salary, annual leave, and other benefits are calculated on a pro-rata basis.

Example: Someone working three days per week (60% of a full-time schedule) is entitled to 60% of the full-time salary and holiday entitlement.

The legal rights of part-time workers

Part-time staff are protected by the Part-Time Workers (Prevention of Less Favourable Treatment) Regulations 2000.

This legislation ensures they are not treated less favourably than their full-time counterparts. That means they are entitled to the same pay rates, access to pensions, training opportunities, and benefits—proportional to the hours they work.

Example: If a full-time employee receives 28 days of paid holiday per year, a part-time employee working half the hours would be entitled to 14 days.

Full-time vs part-time: key differences

The main difference between full-time and part-time work lies in contracted hours:

• Full-time: typically 35–37.5 hours per week.

• Part-time: anything less than a full-time schedule.

Annual leave for full-time employees is at least 28 days (including bank holidays), while part-time employees receive the same entitlement adjusted proportionally.

Both groups have the same employment rights, but part-time work usually offers greater flexibility, making it a popular option for parents, students, or those seeking a better work-life balance.

Practical examples

To put this into perspective:

• A full-time employee working 37.5 hours per week with a salary of £35,000 will work around 1,950 hours per year.

• A part-time employee working three days a week (60%) would earn £21,000, with 16.8 days of holiday entitlement.

• Someone working two days a week (40%) would earn £14,000, with 11.2 days of holiday entitlement.

These calculations demonstrate how pro-rata arrangements ensure fairness while adapting to different working patterns.

Frequently asked questions

How many hours is considered full-time in the UK?

There is no statutory number, but most contracts use 35–37.5 hours as the standard.

Can part-time workers do overtime?

Yes. If they work beyond their contracted hours, they may be entitled to additional pay—particularly if this exceeds the full-time equivalent.

Do part-time employees receive the same pension rights?

Yes. Pension contributions are calculated in the same way, based on earnings.

Can an employer change a contract from full-time to part-time?

No, not unilaterally. Changes to working hours must be agreed with the employee.

How do full-time and part-time working days affect the tax year 2025/26 and 2026/27?

In the UK, the tax year runs from 6 April to 5 April the following year. For both the 2025/26 and 2026/27 tax years, the number of working days will depend on whether you are employed full-time or part-time, as well as the impact of bank holidays and annual leave.

• A full-time employee working five days per week can expect around 260 working days per tax year before deducting public holidays and annual leave.

• Part-time employees’ working days are calculated on a pro-rata basis. For example, someone working three days per week (60% of full-time) would have around 156 working days in a tax year.

This makes it important for both employers and employees to plan ahead when budgeting salaries, holidays, and workload for the upcoming tax years.

Further resources

For more detailed guidance, see:

• ACAS – Working time rules

• GOV.UK – Maximum weekly working hours

• ACAS – Part-time work rights