The four UK tribunal cases that rewrote holiday pay

Ms Brazel was a peripatetic music teacher on a permanent zero-hours contract, working only during term time. The Harpur Trust calculated her holiday pay at 12.07% of earnings, the standard formula for irregular hours. Ms Brazel argued she was a permanent worker entitled to the full 5.6 weeks under the Working Time Regulations 1998, calculated using the 52-week reference period under section 224 ERA 1996.

The Supreme Court unanimously agreed with her. Under the WTR 1998 as drafted at that time, a permanent worker was entitled to 5.6 weeks regardless of how many weeks they actually worked in the year. Result: she was entitled to roughly 17.5% of earnings, not 12.07%.

Mr Lock was a sales consultant whose pay was roughly 60% basic and 40% commission. When he took annual leave he was paid only basic salary, so going on holiday cost him real money. He argued that the Working Time Directive required holiday pay to reflect his "normal remuneration".

The Court of Justice of the European Union agreed: commission that is intrinsically linked to performance of duties must be included in holiday-pay calculations for the EU-derived 4 weeks. The UK Court of Appeal upheld and applied this in 2016.

A group of road workers argued their holiday pay should include non-guaranteed overtime, overtime that the employer doesn't have to offer but, if offered, the worker has to do. They had been paid basic salary only on holiday despite earning substantial regular overtime.

The Employment Appeal Tribunal ruled that non-guaranteed overtime must be included in the 4-week EU-derived portion of statutory leave pay. The court also introduced the "three-month gap" rule: a continuing series of unlawful deductions from wages is broken if there is any gap of three months or more between underpayments.