If you run shifts through zero-hours or low-hours contracts, the way you offer work is about to change. The Employment Rights Act 2025 became law on 18 December 2025 (legislation.gov.uk, 2025), and it hands zero-hours staff three new rights, including a right to be offered guaranteed hours. The fine print is still being settled through a government consultation that closes on 25 August 2026, with the rules themselves due to land in 2027. That gap is your window to get ready.
TL;DR: From 2027, zero-hours and low-hours workers get a right to be offered guaranteed hours reflecting what they regularly work, reasonable notice of shifts, and payment when a shift is cancelled at short notice. A consultation on the detail closes 25 August 2026. Employers should start tracking hours per worker now.
What Is Changing for Zero-Hours Contracts?
The Act does not ban zero-hours contracts. It adds three protections for workers on zero and low-hours arrangements (gov.uk, 2025). First, a right to be offered guaranteed hours that reflect the hours they regularly worked over a set reference period. Second, a right to reasonable notice of shifts, including the day, time and length. Third, a right to payment when a shift is cancelled, moved or cut short at short notice.
Around 1.2 million people in the UK work on zero-hours contracts, about 3.4% of the workforce (ONS, 2025). If you employ shift or casual staff, the odds are good that at least one of them qualifies for these new rights. The concentration is highest in accommodation and food, where 32.2% of the workforce is on zero-hours terms, followed by health and social work at 16.1% (Statista, 2025).
Who Counts as a Qualifying Worker?
A qualifying worker is someone on a zero-hours or low-hours contract who regularly works more hours than their contract guarantees. The government is consulting on where to draw the low-hours line, with a preference for a threshold somewhere in the range of eight to 20 hours a week (Personnel Today, 2026).
Whether a worker qualifies is measured over a reference period. The government's preferred starting point is 12 weeks, though the consultation also asks whether 26 or 52 weeks would work better (Lewis Silkin, 2025). In practice, that means you will need to look at each worker's actual hours across a rolling window, not just what their contract says. What we see most often is employers underestimating how many casual staff have quietly settled into near-regular hours.
How Are Guaranteed Hours Calculated?
At the end of each reference period, you offer the worker a contract with guaranteed hours that mirror what they regularly worked in that window. A worker who averaged 22 hours a week over 12 weeks would be offered a contract reflecting that pattern, rather than staying on paper as a zero-hours employee.
The worker does not have to accept. One question clients always ask is whether a member of staff can turn down guaranteed hours and stay flexible, and the answer is yes. The offer is theirs to take or leave, and it becomes automatically unfair to dismiss someone for accepting or rejecting it, or for trying to sidestep the duty to offer. If a worker declines, you make a fresh offer after the next reference period, so this is not a one-off exercise.
How Much Notice of Shifts Will You Need to Give?
You will need to give reasonable notice of each shift, and the consultation proposes a presumed notice window of somewhere between one and four weeks (Personnel Today, 2026). Fall short of that, and an employment tribunal can weigh whether the notice was reasonable in the circumstances.
There is a financial edge to this too. Cancel, cut short or move a shift at short notice and you will owe the worker a payment, set at a level proportionate to the disruption. In our experience, the businesses caught out by payroll changes like this are the ones running rotas on spreadsheets and goodwill, with no record of when a shift was published or changed. Building a clear audit trail of shift notices now will save arguments later.
Do These Rules Apply to Agency Workers?
Yes. The Act extends guaranteed hours and shift-notice rights to qualifying agency workers, and the responsibility is shared. By default the end hirer, the business actually using the worker, is on the hook for making a guaranteed hours offer, while both the agency and the hirer have duties around shift notice.
If you rely on agency staff to cover peaks, do not assume the agency absorbs all the risk. You may carry the obligation to offer guaranteed hours to a temp who has become a fixture on your rota. It is worth reviewing your agency contracts to see who bears what, because the current terms almost certainly predate these rules.
When Do the New Rules Take Effect?
The substantive rights are scheduled for 2027, with exact commencement dates still to be confirmed. Before then, the government's consultation on thresholds, reference periods and notice windows closes on 25 August 2026, after which regulations will be drafted. Younger workers have the most riding on the outcome, since around one in eight of those aged 16 to 24 are on zero-hours contracts (ONS, 2025).
The 2027 start is not a reason to wait. The reference period that determines who qualifies could look back over 12 weeks or longer, so the working patterns you allow to form in late 2026 may be the ones a first guaranteed hours offer is built on.
What Should Employers Do Now?
Start with visibility, then model the cost. The practical steps that matter before the rules bite:
- Map your zero-hours and low-hours workforce, and flag anyone regularly working stable hours.
- Record actual hours per worker over rolling 12-week periods, so you can see who would qualify.
- Tighten how and when you publish rotas, and keep a record of shift changes.
- Model the payroll cost of converting regular casuals to guaranteed hours, against the cost of keeping flexibility.
- Review your agency contracts to see where the guaranteed-hours duty sits.
Getting your hours data clean is the foundation for all of it. If your payroll and scheduling records cannot tell you who works what across a quarter, you cannot answer the one question these rules turn on.
Frequently Asked Questions
Does the Employment Rights Act ban zero-hours contracts?
No. Zero-hours contracts remain legal. The Act adds a right for qualifying workers to be offered guaranteed hours, plus rights to reasonable shift notice and to payment for short-notice cancellations. Workers can still choose to stay on zero-hours terms if they prefer the flexibility.
When do the guaranteed hours rules start?
The rights are expected to take effect in 2027, with specific dates to be confirmed. The consultation on the detail, including the qualifying threshold and reference period, closes on 25 August 2026.
Can a worker refuse a guaranteed hours offer?
Yes. A worker can decline the offer and remain on a zero-hours contract. It becomes automatically unfair to dismiss or penalise someone for accepting or rejecting the offer, and you must make a fresh offer after each reference period.
What happens if I cancel a shift at short notice?
Once the rules are in force, cancelling, curtailing or moving a shift without reasonable notice will trigger a payment to the worker, set at a level proportionate to the disruption. The exact notice window and payment level are being settled through the consultation.
Do these rules apply to agency staff?
Yes. Qualifying agency workers get the same guaranteed hours and shift-notice rights. The end hirer usually carries the duty to offer guaranteed hours, so review your agency terms to confirm who is responsible.
If you rely on zero-hours or casual staff and want to know how guaranteed hours could reshape your rota and payroll costs, get in touch. We work with UK employers to model the numbers, clean up hours data, and tighten scheduling before the rules take effect in 2027. For related payroll changes already in play, see our guides to statutory sick pay from day one, the National Living Wage payroll checklist, and claiming the full Employment Allowance.