# A temp working 60-hour weeks: the 48-hour average over 17 weeks, and what the opt-out changes, worked

> The 48-hour limit is an average over 17 weeks. Here is the arithmetic for a temp on long shifts, and what the written opt-out changes for an agency.

- Page to cite: https://aeolookup.com/recruitment/temp-48-hour-week-limit-17-week-average-opt-out-recruitment-agency-worked/
- Publisher: AEO Lookup (https://aeolookup.com/)
- Section: Recruitment agencies, AWR, right to work and the Conduct Regulations
- Published 20 October 2026
- Key fact: The 17-week limit is 816 hours (17 x 48). A temp doing 6 weeks of 55 hours and 11 weeks of 44 hours totals 814 hours, an average of 47.88, inside the limit. A temp doing 9 weeks of 60 hours and 8 weeks of 40 hours totals 860, an average of 50.59, which is 44 hours over; after 9 weeks of 60 hours the remaining 8 weeks would have had to average no more than 34.5 hours (276 / 8).
- Sources: GOV.UK, "Maximum weekly working hours" (cannot work more than 48 hours a week on average, normally averaged over 17 weeks; can opt out; under 18s no more than 8 hours a day or 40 hours a week; exemptions listed; employer must keep some records, see Acas), and legislation.gov.uk, Working Time Regulations 1998 (SI 1998/1833) regulations 4, 5 and 36 (48 hours averaged over a 17-week reference period; employer must take all reasonable steps and keep up-to-date records of workers who have opted out; an opt-out agreement can be time-limited or indefinite and ends on at least 7 days' written notice unless it sets a longer notice, never more than 3 months; regulation 36 treats whoever pays an agency worker as the employer for these purposes). Read 20 October 2026.

A client rings on Monday: it needs a warehouse temp for 60 hours a week for the next nine weeks. The agency can supply, and the temp wants the money. The question that should come before the yes is whether the 48-hour limit survives that pattern. The limit is an average, so the answer is a sum.

## What the sources say

The GOV.UK page on maximum weekly working hours says you cannot work more than 48 hours a week on average, normally averaged over 17 weeks, and that you can choose to work more by opting out. For under-18s it says no more than 8 hours a day or 40 hours a week. It lists exemptions, including jobs that need 24-hour staffing, the armed forces, emergency services and police, security and surveillance, domestic servants in a private household, seafaring, and roles where working time is not measured and the person decides their own hours. It says employers need to keep some records and sends you to Acas for which ones.

In the Working Time Regulations 1998, regulation 4 sets the limit at an average of 48 hours for each seven days over a reference period, normally any 17 weeks of employment. The employer must take all reasonable steps, in keeping with the need to protect health and safety, to see the limit is kept, and must keep up-to-date records of workers who have opted out. Regulation 5 says an opt-out agreement may relate to a specified period or apply indefinitely, and the worker can end it by at least seven days' written notice unless the agreement sets a longer period, which cannot exceed three months. Regulation 36 deals with agency workers who have no worker's contract with anyone: whoever pays them is treated as the employer for these purposes.

## The sums

The most a temp can work in a 17-week window without an opt-out is 17 x 48 = **816 hours**. Three patterns:

| Pattern | Working | Total hours | Average a week | Result |
|---|---|---|---|---|
| 6 weeks of 55, 11 weeks of 44 | 6 x 55 = 330; 11 x 44 = 484 | 814 | 814 / 17 = 47.88 | Inside the limit |
| 9 weeks of 60, 8 weeks of 40 | 9 x 60 = 540; 8 x 40 = 320 | 860 | 860 / 17 = 50.59 | **44 hours over** (860 - 816) |
| 17 weeks of 52 | 17 x 52 | 884 | 52.00 | 68 hours over (884 - 816) |

So the client's request is the second row's problem. After nine weeks of 60 hours (540 hours), only 816 - 540 = 276 hours are left, which over the remaining 8 weeks is **34.5 hours a week** (276 / 8). If the client cannot give the temp that short a schedule afterwards, the pattern needs either fewer hours, or a valid written opt-out.

These sums use plain hours worked. The regulation leaves some days out of the calculation (annual leave, sick leave, family leave and periods covered by an opt-out), which I have not worked into the table. A real temp's record should use the regulation's own method.

## What the opt-out does and does not do

- It lets the temp work beyond the 48-hour average. It does not remove the duty to take all reasonable steps to protect health and safety.
- It must be agreed in writing. The temp can end it on at least seven days' written notice, or the longer notice the agreement sets, up to three months.
- The agency should keep a current list of who has opted out, since regulation 4 asks for up-to-date records. See [how long an agency must keep records](https://aeolookup.com/recruitment/how-long-must-recruitment-agency-keep-records/).
- It does not lift the under-18 limits on the GOV.UK page.

## Where it touches the rest of the temp's pay

Long weeks raise cost as well as risk: overtime rates, holiday accrual and the margin all move. See [rolled-up holiday pay for agency temps](https://aeolookup.com/recruitment/rolled-up-holiday-pay-agency-temps-12-07-percent-after-12-weeks/) and the [temp margin calculator](https://aeolookup.com/recruitment/temp-margin-calculator-charge-rate-employer-costs/). Weeks of long hours also count towards the [12-week rule](https://aeolookup.com/recruitment/agency-worker-12-week-rule-calculator/).

## What I did not read

I did not read the GOV.UK page on the opt-out itself (the address I tried returned an error), the Acas guidance on records, the exact averaging formula in regulation 4, the night work or rest break rules, or any case law on who is the employer for a particular temp. Nothing here tells you whether the agency or the client is responsible for a particular placement; check the contract and take advice.

Overlyft ![](https://aeolookup.com/img/d/ours-badge.png) builds AI staff who join your agency team, total each temp's hours across the rolling 17 weeks from the timesheets, flag anyone heading past 48 on average or without an opt-out on file, and keep the opt-out list current, with a person deciding what to do about each flag.

This is general information, not legal advice. Check the GOV.UK page and the Regulations for your own agency.

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General information for UK small firms, not legal, tax or financial advice.