The National Agreement on pay and conditions of service (otherwise known as the Green Book) was updated in March. Since then, we've been contacted by a number of schools worried they have not properly worked out the number of holidays and rate of pay for term-time only staff.

The Green Book states that full time staff should receive at least 31 days holiday, pro-rated for part time staff. The section on term-time only staff provides detailed calculations to help schools calculate the correct accrual rate to apply.

We agree with the maths, but not the explanation which has confused some of our clients worried they are expected to give term-time only staff at least 5.6 weeks' holiday per year.

The guidance refers to the case of Brazel v Harpur Trust. That case did consider the correct rate of accrual for a term-time only teacher, but the real contentious issue is about the rate of pay the school applied. That issue has been appealed and will be heard by the Court of Appeal in May 2019.

The only reason the accrual rate featured in the discussion was because the school made a mistake when drafting the teacher's contract. Instead of giving her 5.6 week' holiday pro-rated to reflect the number of hours she actually taught, it gave her 5.6 weeks' holiday and then tried to reduce this because it disadvantaged full-time workers.

The decision in Brazel doesn't mean that term-time only staff must receive at least 5.6 weeks holiday per year, only that they receive the pro-rated equivalent of the number paid holidays given to comparable full time members of staff.

Getting this wrong can be expensive. We reported in November 2018, that Greenwich Council had settled holiday pay claims for around 5,000 of its term time only staff and has agreed to change the way their holiday pay is calculated going forward. The cost? £3.7 million.

Review your part-time contracts

Unions have made it clear that they will challenge underpayment of holiday for their members and have honed in on term time only contracts. The Green Book reflects their approach to calculating the correct accrual rate.

We recommend that you review your contracts now, particularly if your workplace is unionised to make sure you are giving part time staff the correct number of paid holidays.