You have taken a support worker from an agency to cover a vacancy. She is good, the residents like her, and three months on she is still there. Somewhere around week twelve the rules change, and if you have never used an agency before nobody may have told you what that means. This is the agency workers regulations 12 weeks rule, and it is simpler than it sounds.
Where the 12 weeks comes from
The Agency Workers Regulations 2010 give a temporary worker two sets of rights. The first set applies from the first day of the assignment. The second set only applies once the worker has completed 12 calendar weeks in the same role with the same hirer. Acas sets out both on its agency workers pages and they have not changed since the regulations came in.
From day one, an agency worker is entitled to use the same shared facilities as your own staff, so the canteen, the car park, the staff room and the same crèche or childcare arrangements if you offer them. They are also entitled to be told about any vacancies you advertise internally, in the same way you tell your own people. That does not mean you have to interview them, only that they must be able to see the job exists.
The 12 week period is counted in calendar weeks, not shifts. A worker who does one shift on a Tuesday has done a week. A worker who does five shifts in a week has also done a week. Twelve of those in the same role, with the same hirer, and the equal treatment rights begin.
What equal treatment covers after 12 weeks
Once the worker qualifies, they are entitled to the same basic working and employment conditions as they would have had if you had recruited them directly into that role on day one. In practice that means pay, including any overtime rates, shift premiums and unsocial hours payments you pay your own staff; holiday entitlement, if yours is more than the statutory minimum; rest breaks and the length of the working week; and any bonus that is linked to the individual's own performance rather than to the company as a whole.
It does not cover occupational pensions, occupational sick pay, redundancy pay, notice periods or benefits in kind such as a company car. Those remain the agency's business, or the worker's own.
For a care home the pay point is the one that bites. If your permanent healthcare assistants are on a set hourly rate plus an enhancement for nights, then from week 13 the agency worker on your night rota is entitled to the same rate and the same enhancement. The agency has to pay it. You will usually see it as a change in the charge rate, because the agency's margin sits on top of the worker's pay.
What the hirer has to do
The regulations put the duty to pay correctly on the agency, but the agency can only do that if you tell it what your own staff earn. You are expected to give the agency the pay, hours, holiday and overtime terms for the equivalent role when asked, and to keep that information current. If you have never been asked, it is because the agency has not been doing it properly, not because the duty does not exist. Under the regulations the agency has a defence if it took reasonable steps to get that information from you and you did not give it, and the hirer carries the part of any breach that is down to the hirer.
A sensible habit is to write down the basic terms for each role you use agency staff in, on one sheet, and send it to the agency when the first shift is booked. Hourly rate, night and weekend enhancements, holiday, hours, break arrangements. Update it when your own rates move, which for most homes is April.
When the clock resets and when it does not
The 12 weeks restart if the worker moves to a substantively different role with you, if they go to a different hirer, or if there is a break of six weeks or more between assignments. A break of less than six weeks pauses the clock but does not reset it, so a worker who did eight weeks in June and July, took a fortnight off, and came back in August is on week nine, not week one.
Sickness of up to 28 weeks and jury service pause the clock in the same way, without resetting it. Time off connected with pregnancy, childbirth, maternity, paternity or adoption does not even pause it, and counts as if the worker were still on shift. The regulations also make it unlawful to structure assignments deliberately so that a worker never reaches 12 weeks. Sending someone home in week 11 and bringing them back on a slightly different job title is exactly the pattern the anti avoidance rule is written for.
What is coming next
The Employment Rights Act 2025 adds to this. Acas lists the changes and their dates on its site. From 1 January 2027 the qualifying period for unfair dismissal falls from two years to six months, which matters if you take an agency worker on permanently. During 2027 the zero hours provisions arrive, giving workers a right to be offered guaranteed hours that reflect what they have actually worked, reasonable notice of shifts, and compensation when a shift is cancelled or cut short at short notice. For agency workers the Act makes the hirer responsible for the guaranteed hours offer, not only the agency, so the 12 week sheet described above is worth keeping anyway. It will be the same information you need to answer a guaranteed hours question.
What to do this week
Check how many weeks your current agency staff have done in the same role. Anyone past 12 should be on the same basic terms as your own people, and the agency should have asked you for those terms. If it has not, send them. If you are paying a charge rate that has not moved since week one for someone who has been with you since spring, ask the agency why.
Flamingo Workforce supplies support workers, healthcare assistants and nurses to care providers across the UK. If you would like to talk through how the 12 week rule applies to your rota, use the contact page on this site or call 0330 043 2860.