Guide · Time limits

A series of deductions

Underpaid once, the clock is simple: three months less one day from the payday it happened. Underpaid repeatedly — the miscalculated holiday pay, the unpaid overtime, the missing allowance month after month — and everything turns on one question: do the underpayments form a series? If they do, time runs from the last of them, and the claim can reach back through the lot.

The rule

An unlawful deduction from wages claim must normally be brought within three months (less one day, and subject to the ACAS pause) of the deduction — or, where the claim is about a series of deductions, within three months of the last deduction in the series. That second limb is what makes long-running underpayment claims possible: each new underpayment resets the relevant date, and the series comes in together.

"Deduction" here is broader than it sounds: it covers any shortfall between what was properly payable and what was paid — unpaid wages, underpaid holiday pay, unpaid commission or bonuses that were contractually due, and unauthorised docking all qualify. "Wages" is broadly defined too.

What makes underpayments a "series" — the current law

Whether payments form a series is a question of fact, and the essential glue is a common fault: the underpayments are linked because they flow from the same error, practice or decision — the same wrong rate, the same misclassified status, the same flawed holiday-pay formula — recurring payment after payment.

One point deserves emphasis because a great deal of older commentary on the internet still gets it wrong. For years, following a 2015 appeal decision, it was widely said that a gap of more than three months between underpayments automatically "broke" the series, cutting off everything before the gap. In 2023 the Supreme Court, in a case about police officers' holiday pay, held that this is not the law: a three-month gap does not automatically sever a series. What matters is whether the payments are factually linked by the common fault — their frequency and the gaps between them are relevant circumstances, not a guillotine. If you researched this before 2023 and concluded your older underpayments were unreachable because of a gap, that conclusion is worth revisiting with an adviser.

The two-year backstop

Reaching back is not unlimited. For most deduction claims presented since 2015, a statutory backstop confines the claim to deductions in the two years before the claim is presented, however long the series actually ran. (A few payment types sit outside the backstop, and different considerations can apply to some claims — another reason the "how far back" question belongs with an adviser once the sums are significant.)

Compute your dates →

What to gather while you decide

Series claims are won on paperwork: payslips (every one you can get), your contract and any variation letters, the staff handbook or policy that sets the rate or entitlement, rotas or timesheets showing the hours actually worked, and a simple spreadsheet reconstructing what each pay period should have paid versus what it did. If payslips are missing, you have a statutory right to itemised pay statements, and a data subject access request can retrieve historic pay records your employer holds. Our evidence guide covers how to do this properly.

One strategic note

Small recurring shortfalls compound into significant sums, and employers know that a deductions claim by one person often implies the same claim by everyone on the same terms — which can make these disputes settle faster than their size suggests, and can also make raising it internally first (in writing, keeping a copy) surprisingly effective. Whether to raise it, claim it, or both, and in what order, is a judgment about your circumstances: ACAS (0300 123 1100), your union, Citizens Advice, a law centre, or a regulated adviser can help you make it — free, in the first four cases.