Augustine v Data Cars Limited
| Court | The Supreme Court of the United Kingdom |
| Justices | Lord Lloyd-Jones; Lord Hamblen; Lord Leggatt; Lord Richards; Lady Simler |
| Judgment of | Lady Simler, with whom Lord Lloyd-Jones, Lord Hamblen, Lord Leggatt and Lord Richards agreed |
| Hearing | 7 May 2026 |
| Judgment | 12 August 2026 |
| Appellant | Warren Augustine, a private hire driver |
| Respondent | Data Cars Limited |
| On appeal from | [2025] EWCA Civ 658 |
| Case reference | UKSC/2025/0122 |
| Matter | Whether regulation 5 of the Part-Time Workers (Prevention of Less Favourable Treatment) Regulations 2000 applies where part-time status is an effective cause of the less favourable treatment but not the sole cause |
Summary
Data Cars Limited charged every driver a weekly circuit fee for access to its booking system. The fee was fixed at £148 and did not move with the hours a driver worked, so a driver on short hours paid more for each hour at the wheel. Warren Augustine averaged 34.8 hours a week. He said the fee treated him less favourably as a part-time worker under regulation 5 of the Part-Time Workers (Prevention of Less Favourable Treatment) Regulations 2000.
The answer that defeated him below was that the fee existed so the business could earn revenue, so part-time status was not the sole ground for the treatment. The Supreme Court allowed his appeal. Regulation 5 carries no sole ground test. It is enough that working part time is an effective cause of the treatment complained of. Any other reason goes to objective justification and to what compensation is fair, not to whether the right arises.
Background and facts
Mr Augustine drove for Data Cars Limited as an employee in 2016. Every driver paid the weekly circuit fee to reach the booking dispatch system, at the same rate whatever hours he worked.
The employment tribunal found he worked 34.8 hours a week on average. It made no finding on what counted as full time in that business, but found drivers averaged over 43 hours, some doing 60 or more. His chosen comparator averaged over 90 hours a week, which the tribunal did not hold inappropriate.
The claim failed twice over below. The tribunal held there was no less favourable treatment at all, because every driver paid the same. In the alternative it held that any such treatment was not on the sole ground of part-time status, because a fixed fee was how a private hire business of that kind earned its money. The Employment Appeal Tribunal overturned the first finding by applying the pro rata principle. On the second, the appeal tribunal and the majority in the Court of Appeal both thought the sole ground test wrong in law, and both treated themselves as bound by a 2007 decision of the Inner House of the Court of Session to apply it anyway.
The issue
Whether the right in regulation 5(1) arises only where part-time status is the sole ground for the less favourable treatment, or whether it is enough that it is an effective cause of it.
The decision
The court started with the words on the ground that, settled in discrimination law long before the 2000 Regulations were made. Motive and purpose are beside the point. The question is what caused the treatment.
if the prohibited ground had a significant or substantial influence on or was an effective cause of the impugned treatment or outcome, direct discrimination would be made out. The prohibited ground did not have to be the main ground, still less the sole ground or reason for the treatment.Lady Simler, paragraph 44
The employer's case rested on the European framework agreement of 1997, which protects part-time workers from worse treatment solely because they work part time. Those two words never made it into the 2000 Regulations. The Secretary of State could have used them and chose instead wording lifted from earlier equality statutes the courts had already construed. The court read that choice as deliberate.
Nor did the word only in regulation 5(2) supply a sole cause test. It requires both conditions in that paragraph to be met, and it sits in the wrong place grammatically to qualify the causal link on its own.
Two arguments on causation went nowhere. That a fixed fee was standard in this industry was treated as an argument that everybody was doing the same thing. That the booking software may not have allowed a commission arrangement was speculative. Both belonged, if anywhere, at the justification stage.
The existence of other causes of the treatment may be relevant to the question whether the treatment is justified on objective grounds or to the amount of compensation to be awarded for the unlawful treatment on a just and equitable basis.Lady Simler, paragraph 86
The 2000 Regulations prohibit less favourable treatment of part-time workers where their part-time status is an effective cause of the impugned treatment. It need not be the sole cause.Lady Simler, paragraph 87
Two limits go with the ruling. The court proceeded, as the courts below had, on the footing that part-time status was not the sole ground here. Objective justification was never tested: the employer had told the tribunal it was not seeking to justify the treatment if it was unlawful.
Practical implications
Any charge, deduction or threshold set per head rather than per hour now carries exposure wherever part of the workforce works shorter hours. A fixed weekly plant charge, a flat tool deduction, a fixed contribution to transport or accommodation: each bites harder on the person working fewer hours, and the commercial reason for it no longer stops the claim.
That reason still counts, but it has moved. It is now objective justification, which the employer must plead and prove, rather than a threshold answer that ends the claim.
Thresholds expressed in hours deserve the same review. A bonus that turns on a fixed number of hours, an allowance paid only above a stated attendance level, a qualifying period counted in weeks rather than hours worked: each treats the shorter-hours worker worse, and pro rating is now the starting point.
Practice points
- List every charge, deduction and threshold in your contracts, site rules and payroll that is expressed as a flat amount or a fixed number of hours. That list is the exposure.
- For each one, record now why it is flat and what would be lost by pro rating it. That reasoning is your objective justification, and it has to exist before a claim is brought rather than be assembled afterwards.
- Do not rely on the answer that a flat charge is standard in the industry. The court treated that as an argument that everybody was doing the same thing and gave it no weight on causation.
- Do not rely on treating everyone identically. Identical treatment of workers on different hours is the mechanism of the disadvantage, not a defence to it.
- Where a flat charge cannot be justified, look at a rebate or an adjustment that reflects hours worked. The court accepted that a fee of some kind had to be charged, but not one that ignored hours entirely.
- Check who the comparator population really is. The claimant here compared himself with a driver averaging over 90 hours a week, and the tribunal did not treat that comparison as inappropriate.
- Read the ruling for what it decides. It settles the causation test in regulation 5(2)(a). It does not decide that flat charges are unlawful, and it leaves the structure of the 2000 Regulations narrower than the wider equality legislation.