Your casual gym staff get a right to guaranteed hours in 2027. The number that decides the cost is being picked this summer.

If you staff your gym with casual instructors and zero-hours front desk cover, you will have to start offering some of them guaranteed hours. Not yet. The law passed in December 2025, the rules that make it work are being written now, and the government expects it to bite in 2027. The reason to read this in July 2026 is that the detail deciding how much it costs you is genuinely undecided, the consultation on it closes on 25 August, and the way your rota looks in January is the thing that will set your bill.

Nothing has changed yet, and that is the useful part

The Employment Rights Act 2025 got Royal Assent on 18 December 2025. The zero-hours parts of it have not taken effect. They cannot, because the numbers that make them work sit in regulations nobody has written yet.

The government's own timetable, updated on 16 July 2026, puts guaranteed hours and shift notice in 2027, and says plainly that the timings will be updated after the consultation and that all future dates are subject to parliamentary process. So treat 2027 as the plan, not a promise.

What you get in return for that vagueness is about four weeks of influence. The consultation that decides the detail closes at 11.59pm on 25 August 2026.

Three new rights, in the fewest words possible

• Guaranteed hours. If a casual worker has been working regular hours for you, you have to offer them a contract guaranteeing hours that reflect what they actually worked. They can say no and stay casual.
• Reasonable notice of shifts. You have to tell people when they are working, with enough warning. A tribunal decides what counts as enough.
• Payment for shifts you cancel, move or cut short at short notice. If you pull a shift late, you pay a slice of what they would have earned.

Note the direction of the first one. It is a duty on you to offer, not a right for them to ask. Nobody has to fill in a form for this to land on your desk.

And no, there is no small-business get-out. The consultation proposes exemptions for a handful of narrow situations, such as an employer whose premises are flooded and cannot trade. Headcount is not one of them.

Why this lands harder on a gym than on the shop next door

Two reasons, and they compound.

Your demand moves by season and by hour. January is not March. Tuesday at 6pm is not Tuesday at 2pm. Most gyms solved that with casual labour: a bank of instructors and desk cover you call on when the timetable needs it. That flexibility is the thing being priced.

Then there is who is on the payroll. Nationally, 1.24 million people were on a zero-hours contract in their main job in January to March 2026, 3.6% of everyone in work, according to the ONS. The ONS does not publish a figure for gyms specifically, so be sceptical of anyone who quotes you one. What matters is your own rota, and you already know whether the people opening up and taking the classes are on guaranteed hours or not.

One piece of jargon to get straight, because the rest depends on it. A reference period is just the stretch of time you look back over to work out someone's normal hours. The government's preferred length is 12 weeks. The other options on the table are 26 weeks and 52 weeks.

The January problem, in actual numbers

Here is where a gym differs from almost every other small business, and it is worth doing on paper.

Say the measures switch on, and your 12-week clock starts in January. You staff up for the New Year rush. One of your casual instructors covers 20 hours a week for five weeks while the place is heaving, then settles to 8 hours a week for the seven weeks after as the resolutions wear off.

At the end of that reference period, what do you have to guarantee? It depends entirely on a choice the government has not made yet:

• Mean average: 156 hours over 12 weeks, so 13 hours a week, permanently.
• Median average: the middle of those weeks, so 8 hours a week.

That is the government's own worked example, with the weeks in a gym's order. Same person, same rota, five hours a week of difference, decided by a word in a regulation.

Put money on it. Five extra guaranteed hours a week at the £12.71 National Living Wage for someone 21 or over is £63.55 a week, about £3,305 a year, and employer National Insurance at 15% rides on the part above the £5,000 secondary threshold. Multiply by however many casuals your January rota flatters. Four of them and you are looking at roughly £13,000 a year of labour you now owe in August, when the gym is empty.

Nobody is going to send you extra members to cover that. It comes out of your take-home.

The regularity test is your one real filter. To qualify at all, someone has to have worked in a minimum number of weeks across the period, and the government is consulting on whether that should be 6, 8, 10 or 12 weeks out of 12, possibly alongside a minimum number of hours. The person who covers the odd Saturday will not trigger anything. The instructor who does two classes every single week will.

And rejection is not a one-off escape. If a worker turns the offer down, you may have to make it again after the next reference period. This becomes a recurring administrative job, not a single letter.

Cancelling the 7am class stops being free

This is the part gym owners underestimate, because it feels like normal operations rather than a legal risk.

You pull a class because three people booked. You send someone home at 8pm on a dead Sunday. Under the new right, both of those are things you did, at short notice, and both trigger a payment.

The Act lets ministers define short notice in regulations but caps it at 7 days. The options being consulted on are 1, 2, 3, 5 or 7 days, and the government is considering a second, tighter "very short notice" band with a bigger payment attached.

The payment itself is a percentage of what the person would have earned, either at their actual rate or at the minimum wage rate. The percentages on the table are 10%, 30%, 50%, 65% and 80%, and the Act says it cannot exceed what they would have earned for the shift. The government's own illustration: a 5 hour shift at £14 an hour, cancelled at short notice, at 30% costs you £21.

Twenty-one pounds sounds like nothing. Now count how many times a year you cancel a thinly-booked class or trim a quiet shift, and how many hours are in each. A timetable padded with classes that half-fill is about to have a price on it.

Two things that do not cost you: if the worker cancels, swaps with a colleague or does not turn up, no payment is due. The trigger is you.

On notice, the consultation cites Living Wage Foundation analysis that 54% of workers whose hours vary week to week currently get less than a week's notice of shifts, and CIPD evidence that 45% of employers of low-paid variable workers give a week or less. The options for what will be presumed reasonable are 1, 2, 3 or 4 weeks. If your rota goes up on a Friday for the following week, you are in the group this is aimed at.

The seasonal question they are openly asking, and why you should answer it

Buried in the consultation is a paragraph worth a gym owner's attention.

Limited-term contracts survive. If you take someone on for a specific task, or until a particular event ends, and the contract stops there, no guaranteed hours offer is needed, as long as the limited term was reasonable. Fruit picking until the fruit is picked. Conference staff until the conference ends.

Then the government says something honest: those two definitions may not cover the case where a worker "is only needed until demand decreases (e.g. due to the time of year)". And it asks respondents for examples of temporary need that are not a task or an event.

That is your January, described by the Department for Business and Trade, with a question mark after it. Whether "we hired for the New Year rush and demand fell in March" counts as genuine temporary need is not settled, and they are asking. There are not many moments when a written answer from someone who actually runs a gym can move a number that will sit on your P&L for a decade. This is one, and it expires on 25 August.

For scale, the government's economic analysis from January 2026 estimates around 2.4 million workers are on variable hours contracts, puts the administrative cost of the guaranteed hours right alone at roughly £160 million a year, and classifies both the guaranteed hours measure and the notice-and-cancellation measure as a large cost to business, in the £100 million to £1 billion band.

What a fixed roster does to the price of the gym

Last piece, and it outlives the regulations.

A buyer values your gym on the profit a new owner would keep, your owner earnings, times a multiple. What moves the multiple is how safe that profit looks.

Labour that flexes with demand is a shock absorber. A quiet quarter costs you members but not much payroll. Once a chunk of that labour is contractually guaranteed, the absorber is gone: a soft spring hits your net margin at full force. A careful buyer will notice that your cost base has less give in it than it did, and price accordingly. You can see the shape of it with the valuation calculator.

The flip is real too, and most owners will miss it. A gym that walks into 2027 with a deliberately designed roster, where the guaranteed hours match hours the business genuinely needs every week, looks like a better business than one improvising with casuals, not a worse one. Predictable staffing is easier to hand over. It reads as transferability, which is exactly what a buyer pays for.

The cost is not really the guaranteed hours. It is guaranteeing the wrong ones because a 12-week window picked them for you.