The decision between full-time and part-time work represents a crucial choice that both employers and employees must make. Workers experience three main effects from this decision since it determines their income, work-life balance, and career path.

Businesses use this decision to create their workforce structure, their operational requirements, and their rules, which they must follow. Yet in the UK people still experience difficulties because they do not understand what defines full-time and part-time employment. 

The distinction matters far beyond semantics. The distinction between two things determines how much people get paid and their rights for vacation and their potential to receive benefits and their legal protections. The two parties need to understand these definitions because they will bring major changes to employment law which will become effective in 2026. 

The guide provides clear explanations about full-time and part-time work in the UK. It describes how the law applies to both work categories. It contains essential information that employers and employees need to make their decisions.

What is Full-Time Hours UK?

In the United Kingdom, there is no statutory definition of full-time working hours enshrined in law. The UK does not establish a particular hourly minimum because it uses flexible methods that depend on specific situations. 

According to the GOV.UK, guidance is that a full-time worker will usually work 35 hours or more per week. This statement provides a guideline that should be followed, but it does not create a binding legal obligation. An employer determines what constitutes full-time work through their specific workplace rules and practices, which exist within that workplace or industry.

An example of this is a manufacturing business defining full-time at 40 hours, while an employer might set full-time at 37.5 hours per week for office personnel. A full-time nurse in healthcare may work three 12-hour shifts totalling 36 hours weekly. Consistency is the key: Part-time status is measured against whatever the employer sets as their standard full-time working week. 

This adaptability lets companies customize working schedules to meet their operational needs, but it also compels them to be upfront and honest about what full-time means inside their organization.

How Many Hours Are Full-Time in the UK?

Building on the point above, while 35 hours is the commonly cited benchmark, full-time hours in practice typically range from 35 to 40 hours per week across most industries.

Here are some real-world examples of full-time working patterns:

Source:

It is important to note that the Working Time Regulations 1998 set an upper limit of an average of 48 hours per week over a 17-week reference period, unless the employee has signed an opt-out agreement. For workers under 18, the maximum is 40 hours per week, with no opt-out permitted.

What is Part-Time Hours UK?

By comparison, not by a set hourly limit, a part-time employee is defined. According to the Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000, a part-time worker is one who works fewer hours than a comparable full-time employee doing the same or roughly similar task for the same employer.

Under this relative definition, part-time status can only be viewed considering the job. Anyone hired to work less than 37.5 hours per week—whether 30, 20, or 10 hours—is a part-time employee if an employer’s full-time hours are 37.5. Someone who works 35 hours per week would be deemed part-time if full-time is defined as 40 hours, even though 35 hours may be regarded as full-time elsewhere. 

The laws purposely stay away from stipulating a minimum or maximum number of hours. From retail assistants working 16 hours over four days to teaching assistants working three days a week, this enables the law to fit the wide variety of working habits across several industries.

How Many Hours Is Part Time in UK?

Part-time is determined by comparison, so there is no universal number of hours that qualifies as part-time across all companies. Part-time hours usually fall between 8 and 30 hours per week. 

Often used as a threshold for some benefits and contractual rights, 16 hours per week is a standard reference for part-time employment. Still, this is merely a commonly seen pattern in several companies; it is not a legal definition. 

Legally relevant is not an external criterion but rather whether the individual’s contracted hours are fewer than those of full-time coworkers carrying out the same tasks. Part-time is an employee working 30 hours per week if the employer’s full-time standard is 35 hours. On the other hand, someone working 30 hours might be viewed as full-time in a company where 30 hours is the standard for full-time jobs. 

How Much Time Is Full-Time? (Annualised Hours Consideration) 

Though weekly hours are the most frequent measure, some companies employ annualised hours contracts, where an employee’s overall working hours for the year are agreed in advance, with flexibility to change weekly or monthly hours based on company demands. 

An employee could work more hours during peak seasons and fewer during quieter periods under an annualised hours system if the total annual hours are met. Though the same idea applies—full-time is defined by the employer’s standard arrangement for similar jobs—this complicates determining the full-time level.

For National Minimum Wage calculations, salaried employees are those paid in equal monthly installments. Provided the annual average satisfies the requirement, their hours are averaged over the year, so pay in a hectic month that seems below NMW for the actual hours worked is irrelevant. Employers still have to carefully monitor total hours to guarantee compliance and prevent inadvertent violations.

Are Employment Laws Different for Part-Time Workers?

The fundamental principle of UK employment law is that part-time workers should not be treated less favourably than comparable full-time workers simply because they work fewer hours. 

This means part-time workers have the same statutory rights as full-time workers, applied on a pro rata basis where appropriate. Key areas where equal treatment applies include: 

The Part-time Workers Regulations give part-time workers the right to compare themselves to a full-time colleague doing the same or broadly similar work. If no actual comparator exists, they can compare themselves to a hypothetical full-time worker based on the employer’s policies and practices.

There are limited circumstances where less favourable treatment can be objectively justified—for example, if providing a particular benefit to a part-time worker would be disproportionately costly and the employer can demonstrate a legitimate business aim and proportionate means of achieving it. However, cost alone is rarely a sufficient justification. 

Recent Legal Developments in 2026

The employment law landscape has changed significantly with the Employment Rights Act 2025, which received Royal Assent in December 2025 and is now taking effect throughout 2026. 

Key changes affecting all workers, regardless of hours, include: 

• Unfair dismissal protection now available after six months (reduced from two years) 
• Day-one rights to statutory sick pay, parental leave, and paternity leave  
• Stronger protections for flexible working requests  
• New restrictions on zero-hours contracts, with workers entitled to guaranteed hours where regular patterns have emerged 

These changes mean employers must be even more diligent in managing all workers fairly from day one, with clear probation processes and well-documented performance management. 

Pros and Cons of Full-Time versus Part-Time Hours

Both full-time and part-time arrangements offer distinct advantages and disadvantages for employees and employers. The table below summarises the key points for each perspective. 

For Employees

Full-Time Hours Pros & Cons

Part-Time Hours Pros & Cons

For Employers

Full-Time Hours Pros & Cons

Part-Time Hours Pros & Cons

Salary Comparison of Full-Time versus Part-Time Hours

When comparing salaries, the key principle is that part-time workers should receive the same hourly rate as comparable full-time colleagues. The difference lies in total annual earnings, which are proportionally reduced based on hours worked. 

Full-Time Salary Example

• Role: Teacher 
• Full-time equivalent (FTE): £34,398 – £46,839 per annum  
• Hours: 32.5 hours per week (full-time standard) 

Part-Time Salary Example (Same Role)

• Same role, working 3 days per week (approx. 19.5 hours) 
• Pro rata salary: £20,639 – £28,103 (60% of FTE) 

This pro rata principle applies to most contractual benefits and bonuses. For example, if a full-time worker receives an annual bonus of £1,000, a part-time colleague working 50% hours should receive £500, unless the bonus scheme is structured differently and objectively justified. 

National Minimum Wage/Living Wage (2026): All workers, regardless of full-time or part-time status, must receive at least the statutory minimum rates. As of April 2026, the rates are: 

• 21 and over (National Living Wage): £12.71 per hour 
• 18-20 years: £10.85 per hour 
• 16-17 years and apprentices: £8.00 per hour 

Employers must ensure that part-time workers’ hourly pay never falls below these thresholds when all hours worked are considered. 

Practical Considerations for Employers and Employees

For Employers

1. Clearly define full-time hours in contracts and policies, ensuring consistency across comparable roles 
2. Apply the pro rata principle consistently to pay, holiday, and benefits 
3. Document objective justification for any differences in treatment 
4. Train managers on part-time worker rights and equal treatment obligations 
5. Review policies regularly to ensure they don’t inadvertently disadvantage part-time staff  
6. Monitor working hours carefully, especially for salaried workers who may work unpaid overtime and risk NMW breaches  
7. Consider annualised hours contracts for seasonal businesses, ensuring compliance with the new Employment Rights Act requirements

For Employees

1. Understand your contract—know what full-time means in your workplace and how your hours compare 
2. Know your rights—part-time workers are entitled to equal treatment on a pro rata basis 
3. Request flexible working if you need to adjust your hours; employers must consider requests seriously  
4. Keep records of hours worked, especially if you regularly work beyond contracted hours 
5. Speak up if you believe you’re being treated less favourably than full-time colleagues 

Final Thoughts

The UK system defines full-time work and part-time work through specific number requirements that depend on situations, measurement methods, and the equitable treatment of employees. The standard working week, which an employer establishes, and the employer’s established working week regulations determine employee work hours. Full-time work requires 35 hours or more, and part-time work needs 8 to 30 hours, according to established definitions.

The legal framework protects part-time workers from less favourable treatment, ensuring they receive the same hourly rates, pro rata benefits, and equal opportunities as their full-time colleagues. The Employment Rights Act 2025 now provides increased protection because employers must show their compliance with stronger employment regulations.

Employers need to understand these distinctions because they help with workforce planning, while employees need this knowledge for their employment decisions.

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