On-call vets in the UK: when does on-call count as working time?

On-call at home and on-site duty: two different things.

An on-site duty (the person is at the practice) is working time from start to finish: it uses up hours and needs its rest afterwards. On-call at home is different: the person can be reached, away from the practice, and only the time spent dealing with calls counts as work. That is why they are not planned the same way.

When on-call can become working time.

Before Brexit, the Court of Justice of the European Union treated on-call time at home as working time in the Matzak case (C-518/15, 2018): a firefighter who had to reach the station within 8 minutes. How much weight UK courts give that line today is a question for your adviser. If your on-call rota asks people to be at the practice within a few minutes, check the arrangement with your adviser before treating it as simple on-call.

What to put in writing.

There is no sector-wide agreement for vet practices in Great Britain: working time follows the regulations and each contract. So write down, in the contract or a staff handbook:

• who can be put on call, and how often;
• the response time expected;
• any on-call allowance;
• how time spent on calls is paid and counted.

What it means for the rota.

1. Keep on-site duties (working time) separate from on-call at home on the rota.
2. Count each person’s on-call over the year, not just the month.
3. After a call-out at night, check the rest before a morning shift: 11 consecutive hours in every 24 (regulation 10 of the Working Time Regulations 1998).
4. Leave everyone their weekly rest: 24 hours in every 7 days, or 48 hours in every 14 (regulation 11).

How it works in Djed.

In Djed, on-call is a duty type with its own rotation and its own balance over a rolling twelve months, so it doesn’t always land on the same people. Rest around it (the Monday off after an on-call weekend, for example) is a day-based rule you set as hard, and the engine doesn’t break it. Avoiding two on-call weekends in a row is a goal for the engine, not a guarantee, and Djed doesn’t check the 11 hours, which are counted in hours. It doesn’t record call-outs or work out allowances: those stay with your payroll. More on the on-call page and in the out-of-hours rota method.

Sources and date checked.

• Working Time Regulations 1998 (SI 1998/1833), regulations 4 to 12. Northern Ireland has its own regulations, the Working Time Regulations (Northern Ireland) 2016, with the same limits.
• Court of Justice of the European Union, case C-518/15 (Matzak), judgment of 21 February 2018.

Texts checked on 5 October 2026. This guide is not legal advice: for your own situation, speak to your HR or employment adviser.

Where to go next.

• The limits all of this has to fit inside, under the Working Time Regulations: our working time guide, the reference guide of this series.
• The rest after a call-out, and when it starts: rest after on-call.
• Nights actually worked, and the night-worker limits: night workers.
• Recording call-outs so they can be counted: what regulation 9 still requires.
• Building on-call into the month: the out-of-hours rota method.