Lone working on remote sites: which apps, devices and networks actually work in Scotland?

Why is lone working harder on Scottish sites?

Solar farms, battery storage sites and rural installations are often a long way from the nearest town and, sometimes, from the nearest mast. Engineers visit alone for inspections, fault calls and meter readings. If they fall from a ladder or collapse in a switchroom, the only thing that raises the alarm is the technology in their pocket.

Coverage is the first problem. Ofcom's 2025 figures show 4G from all four mobile networks across 67% of Scotland's landmass, the lowest of any UK nation, against 81% for the UK as a whole. Voice calls from all four networks reach 70% of Scotland's geography (Ofcom, November 2025). Almost every home and business has outdoor coverage; the gaps are exactly where renewables sites tend to be.

The law is the same wherever the site is. The HSE expects employers to assess the risks before anyone works alone, and to have ways of knowing where lone workers are, "pre-agreed intervals of regular contact", devices for raising the alarm, and a reliable way to confirm someone has got back. The HSE also says to "regularly test these systems and all emergency procedures" (HSE).

Which network should your lone workers use?

The best network in Glasgow can be the worst at your site. Choose by the places your people actually work.

• Check each site, not the map. List your regular sites, then check coverage from EE, O2 and Vodafone at each one using the networks' own checkers, and confirm on the first visit with a test call and a test alert.
• Mix networks if your sites are spread out. A team covering Dumfries and Galloway may be best on a different network from one covering Aberdeenshire. Our article on the best mobile network for business in Scotland explains the differences.
• Know what 999 can and can't do. Emergency calls should connect on any network with a signal, but you can't rely on that where there's no mobile signal at all.
• Use WiFi calling at site cabins. Where a site has a satellite or 4G router, WiFi calling lets phones make calls in a cabin with no mobile signal.

Apps, devices or satellite: what works where?

For lone worker services, ask about BS 8484:2022, the British Standard for lone worker services, which covers the device or app, the monitoring centre and how alarms are escalated. Ask any provider exactly how an alarm from a site in rural Scotland reaches Police Scotland or the ambulance service, and how long that takes.

There's no single right product. The right answer depends on the sites, the tasks and the coverage, and many teams end up with two layers: an app or device for everyday check-ins, and satellite as the fallback where there's no signal.

How do you make the system actually work?

The technology is half of it. The rest is the process around it.

Lone working checklist for each site

• Coverage checked on the chosen network, with a test alert from the site itself.
• A fallback where there's no signal: a satellite device, a check-in from the nearest point with signal, or no lone working at that site.
• Check-in intervals agreed for each task, shorter for high-risk work such as working at height or in switchrooms.
• A named person or monitoring centre who acts on a missed check-in, and what they do at 15, 30 and 60 minutes.
• Site access details, grid references and the nearest hospital recorded where the monitoring centre can see them.
• Phones and devices charged, with a vehicle charger and power bank as standard.
• Devices managed through Intune, so a lost phone can be locked and the lone worker app can't be uninstalled.
• A test of the full alarm route, from button press to call-back, at least every quarter.

Worked example: a solar maintenance team

Example (an illustration, not a real client): a solar and battery maintenance company has eight field engineers covering 40 sites across southern and central Scotland, often alone.

A site-by-site coverage check shows that 31 sites have good signal on one network and 6 are better on another, so the company splits its SIMs across two networks by patch. Three sites have no usable signal from any network. Engineers carry a lone worker app with timed check-ins on their managed phones, and a wearable device with fall detection for switchroom and rooftop work. For the three no-signal sites, the company adds satellite messengers and changes the procedure: engineers check in from the last point with signal before arriving and again on leaving. The monitoring centre holds grid references for every site. Each quarter, one engineer triggers a test alarm from a different site, and the office records how long the call-back took.

How Indigo does this. Indigo Unified Communications' mobile team, led by Sales Director Nicola Armstrong, supplies business mobiles on EE, O2 and Vodafone, choosing the network by checking coverage at your sites. We're a leading plan.com partner in Scotland, supply a large range of rugged phones and tablets, and manage devices through Microsoft Intune. We recommend a lone worker app or device case by case, based on where your people work. For site cabins, 4G or 5G is usually live within 2–3 working days. Where there's no signal, we supply Starlink or Eutelsat OneWeb satellite, and satellite services from the mobile networks such as O2 Satellite. Business mobiles for renewables →

What to do next

1. List every site your people visit alone, with a grid reference.
2. Check coverage at each site on EE, O2 and Vodafone, and test on the next visit.
3. Decide a fallback for no-signal sites: satellite, a check-in point, or no lone working.
4. Write the escalation plan for a missed check-in, and test it from a real site.
5. Get a free mobile bill review, and we'll check your networks against your sites at the same time. See also our guide chapter on field teams and mobiles.