How to Send Crowd Updates at an Event
Outdoor 5G is available from at least one operator across 97% of the UK, according to Ofcom (2025). So coverage is rarely why a crowd misses your message. The harder problem is that nobody collected a name, number or address from anyone standing in front of you.
Key Takeaways
- Outdoor coverage isn’t the failure point: Ofcom puts 5G from at least one operator at 97% of the UK (2025). The failure point is capacity at peak.
- Operators already plan for that peak. VodafoneThree says its temporary cells were scheduled to be deployed over 130 times for the 2026 season.
- An event organiser cannot request a government Emergency Alert. GOV.UK restricts sending one to the emergency services and to public bodies that deal with emergencies.
- Martyn’s Law names communication as one of four required procedures, but the Act isn’t in force yet and carries no duty an organiser has to meet today.
- A QR code left in public view is a design decision, not a free win. NCSC has published a warning about QR fraud in open spaces (NCSC, 2024).
What can you actually send to a crowd you have no list for?
Every channel for reaching a crowd falls into one of two families. One reaches almost everyone nearby and carries almost nothing: a shout, a PA line, a sign. The other carries real detail but reaches only the fraction who opted in first: a text, a screen, a code someone scanned. No route on this list does both.
A tour party or a coach group can be briefed before it scatters, which is a different problem, covered in briefing a group you can gather in one place.
Take an illustrative example: a town’s fireworks display, the kind any parish or high street runs once a year. Several thousand people arrive independently over two hours, on foot, by car and by bus, and nobody briefed any of them about anything. When the display ends, one of the two usual exit routes turns out to be closed. The whole crowd has to be turned the other way, at night, with no list of who’s there and no way to have reached them beforehand.
| Route | Who it reaches | What it can carry | Named constraint | Source |
|---|---|---|---|---|
| PA system or loud hailer | Anyone within earshot | One spoken line | No record; range shifts with wind and noise | HSE |
| Screens and printed signage | Anyone who can see and read it | A short instruction or symbol | Needs a sightline and prior understanding of the symbol | HSE |
| Stewards | Whoever they reach in person | A spoken instruction, adapted on the spot | One steward, one place, at a time | HSE |
| Social media or the event’s own app | Existing followers who are looking | Detail, links, updates | Reaches followers, not the crowd | HSE |
| Text to a pre-built list | Only people who gave a number in advance | A full sentence | Needs a list collected before the crowd existed | n/a, a plain constraint of the channel |
| A code scanned on site | Only people who scan it | A short one-way line | Needs a smartphone, a scan, and a code people trust | NCSC |
The PA and the loud hailer
A public address system reaches everyone within its throw, and a loud hailer backs it up if the power fails. Neither leaves a record: once the words are spoken, there’s no way to check who heard them. What happens to a message announced out loud covers how that compares with a screen or a phone alert.
Screens and printed signage
Screens and printed signage work only for people who can see them from where they’re standing, and only if they already understand the symbols. HSE frames signage as one tool among several: “a combination of queuing systems, signage, appropriate barriers and effective stewarding can be used to manage crowd flow/pressure” (HSE, 2025).
Stewards
Stewards are the one channel that can adapt in the moment, redirecting a knot of people before it becomes a crush. HSE stops short of naming a figure, and asks for a judgement instead:
Provide an appropriate number of signposts and/or stewards wearing tabards on the day to direct people to safe walkways, viewing areas and to prevent people from entering prohibited areas. (HSE, 2025)
Social media and the event’s own app
Social media looks like a two-way channel. HSE’s guidance frames it the other way round: “monitoring social media can also provide useful up-to-date information on a crowd’s mood and expectations” (HSE, 2025). That’s the organiser reading the crowd, not the crowd reading the organiser. A post reaches only people who already follow the account and happen to be looking, which at a walk-up event is nobody reliable.
A text to a list you built beforehand
A text reaches whoever gave a number in advance, exactly the group this article is trying to avoid needing. Ticket sales sometimes collect a mobile number; walk-up sales and free entry rarely do. Where a list exists, what texting a list of attendees would cost works through current pricing, which depends on the provider and the volume sent.
A code people scan on site
A code at the entrance or on a screen lets someone opt in the moment they arrive, with no name or number changing hands. It reaches only whoever scans it, and only for as long as they keep checking what it opens.
Coverage is not capacity, and a crowd is a capacity problem
A phone with full signal can still fail to connect when everyone nearby is trying to do the same thing at once. Ofcom’s own coverage checker names the cause: “the capacity of the local mast and congestion in the network, particularly at peak times” (Ofcom). A coverage map shows whether a mast exists. It says nothing about how many phones are already asking it for a slot.
Ofcom names the same effect differently: “network congestion including increased user demand during peak times (such as within commuting hours) impacting the network differently at different times” (Ofcom). Thousands of people checking a screen at the same moment is exactly that peak, concentrated onto one mast rather than spread across a commute.
Operators already build for this rather than hoping it doesn’t happen. VodafoneThree says its temporary cells were “scheduled to be deployed over 130 times” for the 2026 season. EE said its 5G+ network would be activated at “more than 25 major events” over the summer. That targets the moment “when the mobile network is at peak demand as thousands of people try to call, chat, and stream at the same time” (EE, 2026).
| What a coverage map shows | What actually shapes the experience | Source |
|---|---|---|
| Whether a mast is in range | Local mast capacity and congestion, especially at peak times | Ofcom, coverage checker FAQs |
| A single “5G available” tick | A peak in user demand, which isn’t marked on the map | Ofcom, coverage checker FAQs |
| Coverage measured on an ordinary day | Operators trucking in extra capacity for named events | VodafoneThree, EE |
None of this means the network fails at every event. It means a plan whose critical step needs every attendee to have working data at the busiest minute of the night has one point of failure.
Can you get an emergency alert sent for your event?
No. GOV.UK states plainly that “Emergency alerts will only be sent by:” either “the emergency services” or “government departments, agencies and public bodies that deal with emergencies” (GOV.UK). An event organiser, however large the crowd, is neither of those two things.
GOV.UK describes Emergency Alerts as “a UK government system that provides warning and advice in a life threatening emergency” (GOV.UK). It also states plainly that it “will not replace local news, radio, television or social media” (GOV.UK).
It’s also rare in practice. The Cabinet Office reports:
Since the first national test of the Emergency Alerts system in April 2023, five alerts have been sent, including during major storms when lives were at risk. (Cabinet Office, 2025)
The same release states that “there are approximately 87 million mobile phones in the UK” (Cabinet Office, 2025). That’s a count of handsets nationwide, not of people who actually received an alert.
The largest ever use of the system saw approximately 4.5 million people in Scotland and Northern Ireland receive an alert during Storm Éowyn in January 2025, after a red weather warning was issued, meaning there was a risk to life. (Cabinet Office, 2025)
Approximately 3.5 million people across Wales and the South West of England received an alert during Storm Darragh in December 2024. (Cabinet Office, 2025)
What the regulator expects you to have ready
HSE doesn’t assume the PA system will hold up all night, and says so directly. Its guidance names the exact backups it expects an organiser to already have in place, before anything fails.
Provide for any potential failure of electrical communications systems with, for example: spare batteries, mobile phones and/or two-way radios; back-up loud hailers in the event of failure of the public address (PA) system; at larger venues, back-up power supply for the PA system. (HSE, 2025)
Underneath the backup plan sits a baseline duty. HSE states that “you should provide visitors with suitable and sufficient information to help ensure their health and safety” (HSE, 2025).
Having a central location or control point to coordinate the flow of information can assist key decision makers to: gain an overall picture at the venue, eg crowd size, build-up of queues, serious incidents; coordinate the response of all staff responsible for crowd management; coordinate actions with the emergency services and/or other external bodies. (HSE, 2025)
Information doesn’t stop once the gates open, either.
Communicate effectively with the public before, during and after the event, for example by providing information on tickets, websites and via social media about the venue layout and any risks associated with the event activity. (HSE, 2025)
| Route from Table 1 | What breaks it | HSE’s named fallback |
|---|---|---|
| PA system | Power failure | Back-up loud hailers, and back-up power at larger venues |
| Any electrical system | Battery or signal failure | Spare batteries, mobile phones or two-way radios |
| A single decision-maker | No shared picture of the site | A control point coordinating crowd size, queues and incidents |
| Ad hoc updates | Information stopping once the gates open | Communication before, during and after the event |
Martyn’s Law names communication as a procedure
The Home Office’s statutory guidance names communication as one of four required responses, not an optional extra. It states that “the procedures are evacuation, invacuation, lockdown and communication” (Home Office, 2026).
The guidance defines that fourth procedure specifically:
Communication involves providing information to people on the premises or at the event, alerting people to danger and providing instructions, where it is safe to do so. (Home Office, 2026)
None of this is active yet, and the position is stated plainly rather than softened.
The Government intends for there to be an implementation period of at least 24 months following Royal Assent before the requirements for those in scope come into force. (ProtectUK, 2026)
Whilst those that fall within scope of the Act may wish to begin considering the requirements, there is no requirement to comply with them until the legislation comes into force. (ProtectUK, 2026)
| Tier | Threshold (Home Office wording) | What’s required now |
|---|---|---|
| Standard duty | Premises or events expecting between 200 and 799 individuals | No requirement to put in place physical security measures in the standard tier |
| Enhanced duty | Premises or events expecting 800 or more individuals | Not addressed in the sources checked for this article |
Of the four named procedures, three assume something physical: a space to evacuate into, a room to invacuate people towards, a door that locks. Communication is the one a small organiser can start improving with nothing bought and no premises altered, well before any duty applies.
An unmanaged queue is a safety problem, not a service one
A queue that isn’t managed doesn’t just annoy the people waiting in it. HSE puts it plainly:
Inadequate management of queues or delays may cause people to surge towards the doors when they are opened or climb over barriers, leading to overcrowding problems in other areas. (HSE, 2025)
Darkness compounds the same risk. HSE notes that “visitors may be unfamiliar with venue layout and its facilities”. It adds that people “may even become disorientated if they arrive in the light and leave in the dark” (HSE, 2025).
A crowd that has queued for two hours in the dark isn’t the same audience as one that just arrived. Why people give up on a queue covers the psychology behind that shift indoors; outdoors, HSE’s evidence says the same restlessness turns physical faster.
How do you pair with someone who never gave you anything?
An on-site opt-in works the opposite way round from a mailing list. The person chooses to connect at the moment they need updates, rather than months before. A code displayed at an entrance, on a screen or on a steward’s tabard lets someone start receiving messages the second they scan it, with nothing collected beforehand.
That convenience is also the design risk. NCSC warns that “scanning QR codes in open spaces (like stations and car parks) might be riskier” (NCSC, 2024). It adds that “the majority of QR code-related fraud tends to happen in open spaces (like stations and car parks), and often involves an element of social engineering”. An outdoor field at night is exactly that kind of open space.
A code stuck to a lamppost or handed out on a flyer looks identical to one somebody else printed and taped over. Placement is a real decision: on official signage, at eye height, somewhere a steward can vouch for it, rather than scattered loose around the entrance.
Upd8All is one example of this kind of code, and it has real limits at an event this size. The person scanning it needs a phone able to read a QR code and hold a live connection at that moment. Only they can do it, not somebody scanning on their behalf. Channels are strictly one-way, so nobody can reply, and each message is capped at 40 characters, room for one short line.
Under that limit sits the mechanism. No phone numbers or email addresses are exchanged between the business and the customer. Pairing happens by scanning a QR code. There are no accounts and no sign-up, for either side.
The customer does not need the app: scanning the QR code opens the updates in their browser through Upd8 Go. That matters most for a crowd rather than a venue with a settled clientele, since nobody here registered in advance and nothing needs installing before the gates open.
The mechanics behind a QR-paired update channel go into more detail on how the scan itself works. For a venue that already has a queue rather than an open field, where a QR code earns its place in customer service covers the same trade-off close up.
The line you get is shorter than the message you want to send
A crowd in front of you has time for one instruction, not a paragraph. Whatever carries it, voice, screen or scan, the message needs one place and one action, and nothing else. Anything longer competes with noise, low light and a crowd that’s already moving.
Back at the fireworks display, the message that actually needs to travel is short: which exit is shut, and where to go instead. Fitted into one line, that reads “Canal path shut, exit via High St”, 33 characters, short enough for a screen, a sign or a single line of text.
| Timing | Job | Example line |
|---|---|---|
| Before the display starts | Set expectations while people can still choose where to stand | Two exits tonight, arrive either side |
| The moment the route changes | Redirect people who are already moving | Canal path shut, exit via High St (33 characters) |
| Once the site is clear | Confirm it’s safe to leave the usual way | Both exits open now |
What makes a short status update land goes deeper into the wording itself. This table is only about which moment needs which message.
Only what a steward can repeat
The test for any crowd message is whether a steward standing in the middle of it could repeat it correctly to the person next to them. That’s the channel still working when the PA has failed and the network is saturated, at the one minute everyone needed it.
HSE puts the same point on the organiser rather than the hired hand:
While certain aspects of crowd safety can be allocated to contractors, for example stewarding, you retain overall responsibility for ensuring the safety of the public. (HSE, 2025)
Contracting out the stewarding doesn’t contract out the judgement.
That 97% coverage figure from the start of this article was never wrong. It just answers a question a crowd this size was never really asking.
Frequently Asked Questions
Can an event organiser send a government emergency alert?
No. GOV.UK names two categories of sender: the emergency services, and government departments, agencies and public bodies that deal with emergencies. No matter how many tickets were sold, an organiser doesn’t fall into either category. The service exists for warning and advice in a life-threatening emergency, and it doesn’t replace local news or social media.
Will the mobile network cope at a busy event?
Not automatically. Ofcom’s coverage checker names local mast capacity and network congestion at peak times as the main things affecting a crowded event. That’s separate from whether a mast is in range at all. A full signal bar only confirms the mast is there, not whether it can serve everyone reaching for it in the same minute.
Does Martyn’s Law apply to a small community event?
It may, once it’s in force, though it isn’t yet. The Home Office’s guidance sets a standard duty for premises or events expecting between 200 and 799 individuals, and an enhanced duty from 800 or more. ProtectUK is explicit that there’s no requirement to comply with either tier until the legislation comes into force.
What is the fastest way to tell a crowd that an exit has changed?
Usually a person, not a screen or a phone. A steward standing at the junction, redirecting people as they arrive, adapts in real time in a way no broadcast channel does. HSE’s own guidance treats stewards and signposting as core crowd controls, not a backup. Anything electronic still depends on someone having a working phone at that exact moment.
Sources
- HSE, Crowd controls inside the venue, last updated 4 April 2025, retrieved 2026-08-31, https://www.hse.gov.uk/event-safety/crowd-management-control-inside.htm
- HSE, Put crowd controls in place, last updated 4 April 2025, retrieved 2026-08-31, https://www.hse.gov.uk/event-safety/crowd-management-controls.htm
- HSE, Assess crowd safety risks and identify hazards, last updated 4 April 2025, retrieved 2026-08-31, https://www.hse.gov.uk/event-safety/crowd-management-assess.htm
- HSE, Set clear roles and responsibilities, last updated 4 April 2025, retrieved 2026-08-31, https://www.hse.gov.uk/event-safety/crowd-management-roles.htm
- HSE, Monitor the crowd, last updated 4 April 2025, retrieved 2026-08-31, https://www.hse.gov.uk/event-safety/crowd-management-monitoring.htm
- Home Office, Terrorism (Protection of Premises) Act 2025: statutory guidance, updated 25 August 2026, retrieved 2026-08-31, https://www.gov.uk/government/publications/the-terrorism-protection-of-premises-act-2025/terrorism-protection-of-premises-act-2025-statutory-guidance
- ProtectUK, Martyn’s Law overview and what you need to know, published 15 April 2026, retrieved 2026-08-31, https://www.protectuk.police.uk/martyns-law/martyns-law-overview-and-what-you-need-know
- GOV.UK, About Emergency Alerts, retrieved 2026-08-31, https://www.gov.uk/alerts
- Cabinet Office, National emergency alert test to be held on 7th September, published 7 July 2025, retrieved 2026-08-31, https://www.gov.uk/government/news/national-emergency-alert-test-to-be-held-on-7th-september
- Ofcom, Map Your Mobile coverage checker: FAQs, retrieved 2026-08-31, https://www.ofcom.org.uk/mobile-coverage-checker/frequently-asked-questions
- Ofcom, Brits devour data at record levels as mobile networks race to improve 5G, published 19 November 2025, retrieved 2026-08-31, https://www.ofcom.org.uk/phones-and-broadband/coverage-and-speeds/brits-devour-data-at-record-levels-as-mobile-networks-race-to-improve-5g
- VodafoneThree, VodafoneThree network COWs (Cells on Wheels) are coming to a 2026 event near you, published 25 March 2026, retrieved 2026-08-31, https://www.vodafonethree.com/cells-on-wheels-2026-events/
- EE / BT Newsroom, From the stage to the seaside: EE supercharges summer to give millions the edge with 5G+, published 1 June 2026, retrieved 2026-08-31, https://newsroom.ee.co.uk/ee-supercharges-summer-to-give-millions-the-edge-with-5g-plus/
- NCSC, QR codes: what’s the real risk?, published 8 February 2024, retrieved 2026-08-31, https://www.ncsc.gov.uk/blog-post/qr-codes-whats-real-risk