Most workers can carry over up to 4 weeks of statutory annual leave if they couldn’t take it due to sickness or family-related leave (usually within 18 months), or if their employer failed to give them a reasonable chance to take it. Since the 2024 reform of the Working Time Regulations, irregular-hours and part-year workers also have their own accrual and carry-over provisions, and the old COVID-19 carry-over allowance no longer applies.

Key Takeaways

• The Employment Rights (Amendment, Revocation and Transitional Provision) Regulations 2023 amended the Working Time Regulations 1998, in force from 1 January 2024, with most changes applying to leave years starting on or after 1 April 2024.
• Carry-over of the 4-week EU-derived portion of statutory leave remains protected when a worker is off sick, on family-related leave, or wasn’t given a genuine opportunity to take it.
• Irregular-hours and part-year workers now accrue leave at 12.07% of hours worked per pay period, and employers can (optionally) use rolled-up holiday pay for this group.
• The temporary COVID-19 carry-over rules were formally removed by the reform — that emergency allowance no longer exists for current leave years.
• Employers can always offer more generous contractual carry-over than the statutory minimum, but never less.

What Changed in 2024: The WTR Reform in Brief

The Working Time Regulations 1998 have governed UK annual leave for decades, but by 2023 the rules had become a patchwork of case law — particularly around how leave should be calculated for workers with variable hours. The government addressed this through the Employment Rights (Amendment, Revocation and Transitional Provision) Regulations 2023, which took effect on 1 January 2024.

According to GOV.UK guidance, the reform did three things: it gave irregular-hours and part-year workers a defined accrual method and optional rolled-up holiday pay, it codified into the Regulations the carry-over rights that previously existed only through Court of Justice of the European Union and UK case law (sickness, family leave, and an employer’s failure to enable leave-taking), and it removed the temporary COVID-19 carry-over provisions for leave years ending 2020–2022. Most changes apply to leave years starting on or after 1 April 2024.

If you need the pre-reform basics — how the 5.6-week entitlement splits into two portions with different default carry-over treatment — see our companion guide on carrying over annual leave in the UK. This article focuses specifically on what the 2024 reform changed.

How Much Annual Leave Can You Carry Over?

For the large majority of workers with fixed or regular hours, the statutory carry-over position is unchanged in substance — the reform simply put existing case-law protections into the Regulations themselves. According to ACAS guidance, a worker can carry over up to 4 weeks of their statutory leave (the EU-derived portion, out of the full 5.6-week UK entitlement covered in our annual leave entitlement guide) in the following circumstances:

• Sickness — the worker was unable to take leave because they were off sick. This carried-over leave must generally be used within 18 months of the end of the leave year in which it was accrued.
• Family-related statutory leave — maternity, paternity, adoption, shared parental, or parental bereavement leave prevented the worker from taking their annual leave.
• Employer failure to facilitate leave-taking — the employer didn’t give the worker a reasonable opportunity to take their leave, didn’t encourage them to take it, or didn’t warn them that unused leave would be lost.

Outside these circumstances, the additional 1.6 weeks of UK-only statutory leave still only carries over if your contract or leave policy allows it. One 2026 detail worth flagging: from 6 April 2026, employers must keep records of holiday entitlement and pay — including carried-over leave — for at least six years, so carry-over decisions now need a proper paper trail.

New Carry-Over Rules for Irregular-Hours and Part-Year Workers

The most significant practical change targets workers whose hours vary week to week — casual staff, zero-hours contracts, and term-time-only roles. Before 2024, calculating their leave accurately was genuinely difficult, and the “percentage method” employers had long used sat in a legal grey area. The reform put that method on a statutory footing: for leave years starting on or after 1 April 2024, irregular-hours and part-year workers accrue annual leave at 12.07% of the hours they actually work in each pay period, capped at the equivalent of 5.6 weeks.

Two carry-over consequences follow:

1. Carry-over rights still apply to this group in the same protected circumstances as everyone else — sickness, family leave, and an employer’s failure to facilitate leave-taking — calculated against leave accrued under the 12.07% method.
2. Rolled-up holiday pay is now permitted for irregular-hours and part-year workers only. If an employer chooses it, holiday pay is paid as an extra 12.07% uplift alongside normal wages each pay period rather than when leave is taken. It’s optional, and if used, there’s no leave “balance” left to carry over for that pay — the entitlement is paid out as it accrues.

If you employ anyone on irregular or part-year contracts, run their entitlement through our UK holiday entitlement calculator and cross-check it against our part-time holiday entitlement guide — the 12.07% method and the older pro-rata approach can produce different numbers.

Employer Discretion Beyond the Statutory Minimum

Everything above is the legal floor, not a ceiling. If you offer more than the statutory 5.6 weeks — 25 days plus bank holidays is common — the extra days sit outside the Regulations entirely. You decide whether they carry over, how many, and for how long, through your employment contract or leave policy. The statutory protections exist for genuine hardship (illness, family leave, being denied the chance to book time off); a sensible contractual allowance is what smooths out ordinary scheduling friction so employees aren’t scrambling in December.

How to Set Your Own Carry-Over Policy

A clear, written policy prevents most carry-over disputes before they start. When drafting or updating yours:

1. State the leave year clearly, separating the statutory minimum from any additional contractual leave.
2. Set a contractual carry-over allowance — commonly 3–5 days — with a firm expiry date (e.g. 31 March) so it doesn’t roll forward indefinitely.
3. Reference the statutory protections explicitly so employees know sickness and family leave sit outside the contractual cap.
4. Build in quarterly reminders of remaining balances — this also evidences a “reasonable opportunity” to take leave.
5. Keep records of every carry-over decision, now that the record-keeping requirement is in force.

For a fuller walkthrough of building a compliant policy end to end, read our guide to writing a UK leave policy that meets employment law.

FAQ

How many days of annual leave can I carry over in the UK?

Up to 4 weeks (20 days full-time) of statutory leave if you couldn’t take it due to sickness, family-related leave, or your employer not giving you a reasonable opportunity to take it. Leave above the statutory 5.6 weeks carries over only if your contract allows it.

Did the 2024 reform change how much leave I can carry over?

Not for most regular-hours workers — the reform mainly codified existing case law. The bigger change is for irregular-hours and part-year workers, who now have a defined 12.07% accrual method and, optionally, rolled-up holiday pay.

Can my employer refuse to let me carry over leave?

Only outside the protected statutory circumstances. If you were sick, on family-related leave, or genuinely weren’t given the chance to take your leave, your employer cannot lawfully refuse carry-over of that statutory portion.

Is the COVID-19 carry-over allowance still available?

No. The 2024 reform formally removed the temporary COVID-19 carry-over provisions. Leave carried over under those 2020–2022 rules should already have been used.

Do irregular-hours workers get the same carry-over rights as everyone else?

Yes for the protected circumstances — sickness, family leave, and failure to facilitate leave-taking still apply. The difference is how their entitlement is calculated (12.07% of hours worked per pay period) and that employers may choose rolled-up holiday pay instead of a traditional balance.

Keep Carry-Over Rules Straight Without the Spreadsheet

Tracking two accrual methods, three statutory carry-over triggers, an 18-month sickness deadline, and your own contractual allowance is a lot to hold in a spreadsheet — especially with record-keeping obligations on top. Leave Balance calculates entitlement automatically for regular and irregular-hours workers, flags carried-over leave and its expiry date, and keeps an audit trail of every decision.