What is the guaranteed hours right?
The guaranteed hours right is a new provision under the Employment Rights Act 2025. It does not ban zero-hours contracts or force workers onto fixed schedules. What it does is require employers to offer a contract that reflects reality — specifically, the hours a worker has actually been working — at the end of each reference period.
If someone has been coming in four days a week for three months and their contract says zero guaranteed hours, you will be legally required to offer them something closer to what they are actually doing. They can turn it down. But you have to make the offer.
The reference period is expected to be 12 weeks, though secondary legislation is still being developed. The government confirmed in early 2026 that it is working towards a 2027 implementation date, but has not yet set a specific day.
Who qualifies?
The right applies to zero-hours workers and low-hours workers — people whose contracts either guarantee no hours at all, or guarantee fewer hours than they are regularly working in practice. The precise qualifying conditions are still being set out in secondary legislation.
Agency workers are also expected to gain this right in 2027, which has implications for businesses that rely heavily on agency cover. If the same agency workers show up to your site week after week, that pattern is acquiring legal significance.
Worth noting: The government has included provisions specifically to prevent employers from using short reference periods or deliberate scheduling gaps to avoid the obligation. The law is designed to capture genuine regular patterns, not just whatever happened in the most recent 12 weeks.
What happens at the end of a reference period?
When a qualifying worker completes a reference period, the employer must make a guaranteed hours offer. That offer must reflect the hours the worker actually worked during the period — not what the contract says.
The worker then has a choice. They can accept the offer, in which case their contract is updated. Or they can decline, in which case they continue on their existing arrangement. There is no obligation on the worker to accept fixed hours — the flexibility cuts both ways.
What the employer cannot do is fail to make the offer at all. That is where the liability sits.
Why does this matter right now if 2027 is still months away?
Because compliance is calculated from data — and that data only exists if you have been recording it.
When the guaranteed hours obligation comes into force, you will need to show what each qualifying worker actually worked over their reference period. If your shift records live on WhatsApp, a spreadsheet that gets overwritten each week, or a manager's memory, you have no usable data.
Worse, if a worker claims you failed to make the required offer and you cannot demonstrate what hours they worked, you cannot defend yourself.
The businesses that will handle this well are those that start logging every shift — with actual start and end times, against the specific worker — from now. That gives you 12 months of clean records before the first reference period obligation potentially falls due.
FlexiWork builds your compliance records automatically
Every shift clocked in FlexiWork is recorded against the worker in real time. Your 12-week rolling pattern data is there when you need it — no spreadsheets, no reconstruction, no gaps.
Start free — 30 daysWhat to do now
You do not need to change your contracts or your workforce model today. What you do need to do is put yourself in a position to comply when the obligation arrives.
- Start recording actual hours worked for every zero-hours and casual worker, with real start and end times per shift — not just scheduled hours.
- Track this against individual workers, not just shifts. You need to be able to pull up a 12-week picture for any given person at any point.
- Review your agency arrangements. If the same agency workers come to your site regularly, start mapping that relationship now. The guaranteed hours right is expected to extend to agency workers in 2027.
- Think about your current contracts. If you have workers who have been doing consistent hours for years and are still on zero-hours arrangements, ERA 2025 is a prompt to consider whether those arrangements still make sense — commercially and legally.
- Watch for the secondary legislation. The government will confirm the exact reference period, qualifying conditions, and implementation date through regulations. Subscribe to ACAS updates or check acas.org.uk for the latest.
Common mistake: Assuming that because the obligation is not live yet, you have nothing to worry about until next year. The reference period is backwards-looking. When the right comes into force, the calculation starts from data that should already exist. If it does not, you are already behind.
What does this mean for your workers?
Most workers on zero-hours contracts in hospitality, retail, and events already know roughly how many hours they work each week — even if their contract says nothing. ERA 2025 formalises that reality.
For workers who want more certainty, this is a meaningful change. For workers who value flexibility — and many do, particularly students and those with caring responsibilities — the right to decline the guaranteed hours offer means they keep their flexibility if they choose.
In practice, this is likely to prompt conversations you should probably be having anyway: which of your zero-hours workers actually want a regular schedule, and which prefer the current arrangement? Getting ahead of those conversations is better than having them under legal pressure in 2027.