Backdated Holiday Pay Claims 2026/27: The 2-Year Backstop and How to Calculate Arrears

What counts as backdated holiday pay

Backdated holiday pay arises when an employer has, for some period, paid workers less for their annual leave than the law required — most commonly by calculating holiday pay from basic salary alone while ignoring regularly worked overtime, commission, or other guaranteed pay elements that should have been included in the average.

This is treated in law as an unlawful deduction of wages under the Employment Rights Act 1996: the gap between what was actually paid and what should have been paid is the "deduction," and it can be recovered through an employment tribunal claim, or in some cases through the civil courts as a breach of contract.

The principle that regular overtime and commission must be reflected in holiday pay was established through a string of EU-derived case law — most notably Williams v British Airways (allowances that form part of normal remuneration) and Lock v British Gas (commission) — which UK tribunals have applied consistently since. If your holiday pay has only ever reflected your basic salary and you regularly work paid overtime, there's a reasonable chance you've been underpaid.

Worked example 1: calculating the weekly shortfall

Consider a warehouse worker, Dan, on a basic salary of £2,100/month (£24,865.20/year on a standard hourly conversion) who also regularly works overtime averaging £280/month over the past year.

If Dan took 20 days (4 weeks) of holiday during the period under review, the arrears would be roughly 4 × £64.61 = £258.44 for that year alone. Run your own basic-versus-full-pay comparison through

to see what your holiday pay should look like before working out how much has been missed.

The 2-year backstop: how far back you can actually claim

Since 1 July 2015, the Deduction from Wages (Limitation) Regulations 2014 have limited unlawful deduction of wages claims — including holiday pay arrears — to a maximum look-back of 2 years from the date the tribunal claim is lodged. This applies regardless of how long the underlying underpayment has been happening.

So if Dan has actually been underpaid in this way for 6 years, but only brings his claim now, he can typically only recover arrears for the most recent 2 years, not the full 6. This backstop was introduced specifically in response to concerns about the scale of historic holiday pay liabilities employers faced after early case law established the overtime-inclusion principle.

Worked example 2: the backstop in practice

Priya has been underpaid holiday pay by an average of £45/week of leave taken, consistently, for the last 5 years. She takes her full 28 days (5.6 weeks) of statutory leave every year.

The backstop cuts Priya's recoverable arrears by well over half, even though the underpayment pattern was identical throughout. This is the single most important practical constraint on backdated holiday pay claims, and it's why bringing a claim sooner rather than later matters — every month of delay is a month of potential arrears that drops out of the claimable window.

Does a gap in holiday-taking break the claim? The Agnew ruling

Before 2023, employers sometimes argued that if a worker went more than 3 months between periods of underpaid holiday, the "series" of deductions was broken, resetting the clock and limiting the claim to whatever fell within 3 months of the most recent deduction. This approach came from the Employment Appeal Tribunal's decision in Bear Scotland v Fulton.

The UK Supreme Court's 2023 decision in Chief Constable of the Police Service of Northern Ireland v Agnew rejected that approach. The Court held that a gap of more than 3 months between deductions does not automatically break the series — what matters is whether the deductions share a common fault or unifying factor (such as a consistent method of calculating holiday pay that excludes overtime). This is significant for workers whose holiday-taking is naturally uneven across the year, because it means a claim can still capture the full pattern of underpayment, subject always to the 2-year backstop measured from the date the claim is lodged.

Worked example 3: employer costs and Employment Allowance context

Backdated holiday pay claims aren't just a worker-side calculation — they carry real cost for employers too, and understanding that context helps explain why many employers now correct their holiday pay methodology proactively rather than wait for claims.

On top of the gross arrears, an employer correcting historic underpayment must also account for employer National Insurance at 15% on the additional amounts paid (above the £5,000/year secondary threshold per employee), though Employment Allowance can offset up to £10,500 of a qualifying small business's total annual employer NI bill. For a business with dozens of affected staff, a systemic holiday pay error can therefore represent a five-figure liability even before legal costs, which is one reason many employers now review their

methodology after a pay-structure change such as introducing regular overtime or a new commission scheme.

Which weeks of leave does the claim cover?

Not all statutory holiday is treated identically for arrears purposes. UK workers are entitled to 5.6 weeks of statutory annual leave, made up of:

Because the strongest legal basis for including overtime and commission applies to the first 4 weeks, many backdated holiday pay claims focus arrears calculations on that portion first, with the remaining 1.6 weeks and any contractual extra leave assessed separately depending on what the employment contract or company handbook says.

How to bring a claim

To bring a backdated holiday pay claim, you generally need to notify ACAS for early conciliation and then lodge an employment tribunal claim within 3 months less one day of the last deduction in the series, or the date your employment ended if that's later. Gather payslips covering at least the 2 years before you expect to submit the claim, a record of the holiday you actually took in that period, and anything showing your contract's holiday pay policy. If your employer disputes the figures, a tribunal can order disclosure of payroll records to establish the correct averages.

Bottom line

If your holiday pay has never reflected regular overtime, commission, or other guaranteed pay, you likely have a claim — but the 2-year backstop means the clock is effectively running against you every day you wait. Work out your correct weekly holiday pay using

, compare it against what you've actually received, and act promptly, since delay directly shrinks the window of arrears you can recover.