Contractors on site: what you owe them before they start

The callout engineer arrives at 11pm. The gearbox on the main conveyor has let go and the line's been stood since nine.

Security has no name on the list. The shift manager is on the floor. Twenty minutes later someone finds an induction video, but the laptop won't play it. Nobody can say where the isolator is, which permit the job needs, or what's been tried. The engineer stands in the gatehouse. You're paying for that time, and the line still isn't moving.

When it finally starts, nobody has told the engineer about the forklift route that cuts across the walkway to the conveyor.

Most sites think of contractor safety as the contractor's problem. The law doesn't agree. And the things it asks of you are the same things that get the job started faster.

Your duties stay with you

The Health and Safety at Work Act puts a duty on every employer towards people who aren't their employees. You must run your business so that, so far as is reasonably practicable, those people aren't exposed to risks to their health or safety (section 3). A contractor on your site is one of those people.

HSE's leaflet on contractors defines one simply: "anyone you ask to do work for you who is not an employee" (INDG368). It also says the leaflet doesn't cover temporary or agency workers, who have their own rules. Our post on health and safety duties to agency workers covers that side.

The Management Regulations add two duties that bite here. You must give the contractor's employer "comprehensible information" on the risks from your operation and the measures you take (regulation 12). The same applies to a self-employed engineer. And where two employers share a workplace, even for a few hours, each must co-operate and co-ordinate with the other (regulation 11). We go further on this in shared workplaces.

Check they can do the job

INDG368 says you must satisfy yourself the contractor can do the job safely. That means asking about their skills, experience and knowledge, with the depth of questions set by the risk and complexity of the work (INDG368).

It lists questions worth asking. How will the work be managed and supervised? Will they use subcontractors? What qualifications and experience do they have in this type of work? Do they have a written health and safety policy? That one is only required by law if they employ five or more people*.

Its own advice is short: "Don't assume someone is competent, check it yourself."

For a breakdown, do this before the night it happens. At 11pm you can't vet a stranger. You need engineers whose tickets, insurance and experience you checked on a quiet Tuesday. That's the cost of not having the right engineer lined up: the line waits while you find one, and then you hope.

Tell them what can hurt them

Both of you assess the risks. Then you sit down together and look at how each other's work could affect people (INDG368). In practice that's a short conversation at the machine.

INDG368 says the contractor and their staff need information on the risks they may face, the measures in place, and your emergency procedures. And it gives a blunt line: "Don't assume that contractors will be aware of all risks, even if they seem obvious to you."

On a factory or warehouse site, the risks a visiting engineer won't know are usually the same few:

• forklift and pedestrian routes near the job
• other isolations or work going on nearby
• what's in the pipework or the tank
• fragile roofs, pits and overhead cranes
• where the alarm sounds, where to muster, and who the first aider is

Send what you can before they set off. Our post on what to have ready before the callout engineer arrives has the full list.

Sign in, named contact, then start

HSE's longer guide, Managing contractors (HSG159), sets out five steps. The third is about the job itself: all contractors sign in and out, name a site contact, go over the site rules, check the job and allow work to begin (HSG159).

The site contact should be someone in a managerial position "with sufficient authority and competence". They go over the job with the contractor, check whether a permit is needed, and agree how the job will be supervised.

HSG159 also warns: "Don't let contractors or their subcontractors turn up and just get on with the job, even if they were there the day before." Things change overnight.

None of this needs an hour. A two-minute brief at the gate covers most of it. Our post on briefing a contractor at the gate shows how. For permit jobs, see permits to work.

Keep a check while they work

The contractor supervises their own work. But you can't leave them to it and pay at the end. HSG159 quotes HSE that supervision of contractors "may need to be greater than that for permanent employees" if safe systems are to be followed (HSG159).

INDG368 also asks you to agree how work will be stopped if there are serious health and safety concerns (INDG368). Agree it up front. Then nobody argues about it at 1am.

Is it construction work?

Sometimes it is. Under CDM 2015, construction work includes the installation, maintenance, repair or removal of mechanical, electrical, compressed air and similar services "normally fixed within or to a structure" (CDM 2015, regulation 2). A bigger job on fixed site services can bring extra duties for you as the client. If you're not sure, check before the work is let.

Our view

Every step here pays you back. The sign-in tells you who's on site in a fire. The brief stops the engineer walking into a forklift. The pre-checked list of engineers means the line restarts an hour sooner. Sites that treat contractor safety as paperwork lose time on every callout. Sites that build it in get faster.

What to do on Monday

1. Write a one-page contractor brief for your site: hazards, routes, alarm, muster point, first aider, who signs permits.
2. Name a site contact for every shift, with authority to start and stop contractor work.
3. Build a short list of callout engineers you've already checked: competence, insurance, tickets.
4. Agree with security what happens when a contractor arrives out of hours, including who they call.

* The five-employee threshold for a written health and safety policy correct as of 13 September 2026. Check HSE's Using contractors leaflet (INDG368) for the latest.