Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000

A part-time worker has the right not to receive less favourable contract terms, or suffer another detriment, compared with a comparable full-time worker. The difference must be on the ground that the worker is part time and must not be justified on objective grounds.

The definition of worker is wider than employee. It can include an individual who agrees personally to perform work or services, unless the other party is a client or customer of the individual's own business undertaking.

This instrument applies in Great Britain. Northern Ireland has separate Part-time Workers (Prevention of Less Favourable Treatment) Regulations (Northern Ireland) 2000.

In most cases, the worker must identify an actual full-time comparator employed by the same employer. Both people must work under the same type of contract and perform the same or broadly similar work, taking qualifications, skills and experience into account.

The comparator should normally work at the same establishment. A worker at another establishment can be used if there is no suitable full-time worker at the part-time worker's location. Limited exceptions apply when someone moves from full-time to part-time work or returns part time within 12 months after an absence.

When a comparable full-time worker receives pay or another benefit, the pro rata principle generally gives the part-time worker at least the proportion that their weekly hours bear to the comparator's weekly hours. The principle applies unless it is inappropriate.

Regulation 5 also allows an employer to show that different treatment was justified on objective grounds. That is a separate question from whether the worker was treated less favourably on the ground of part-time status.

There is a specific overtime qualification. A lower overtime rate is not, by itself, less favourable treatment where the part-time worker's total hours in the relevant period do not exceed the comparable full-time worker's normal hours.

Data Cars charged all private hire drivers GBP 148 a week to access its booking system. Warren Augustine averaged 34.8 hours a week, while his full-time comparator worked over 90 hours. The same fee therefore cost Mr Augustine more for each hour of access and left him with a smaller proportion of earnings.

On 12 August 2026, the Supreme Court held that part-time status did not need to be the only cause of that treatment. It was enough that part-time status was an effective cause. Other commercial or technical explanations may still be relevant to objective justification.

A worker who believes regulation 5 may have been breached can ask in writing for the reasons. The employer must provide a written statement within 21 days. The statement is admissible in tribunal proceedings, and a tribunal may draw an adverse inference if the employer deliberately fails to respond without reasonable excuse or gives an evasive or equivocal written statement.

The Regulations protect employees from unfair dismissal, and workers from detriment short of dismissal, for using these rights. That includes bringing proceedings, requesting reasons, giving evidence or information, otherwise doing anything under the Regulations, alleging an infringement, refusing to give up a protected right, or where the employer believes or suspects they have done or intend to do those things. There is a limited exception where an allegation was false and not made in good faith.