999 Calls on VoIP: What Ofcom Requires Businesses to Know

Ofcom requires every VoIP provider that connects to the phone network to allow 999 and 112 calls free of charge, and to supply the caller's location to the emergency services wherever it's technically possible to do so. Providers also have to offer a way of reaching emergency services for at least one hour during a power cut, for customers who depend on the service. For businesses, the practical takeaway is that a properly set up VoIP system should handle 999 calls reliably — but it's worth confirming this has actually been configured correctly for your specific setup, particularly if you have more than one site.

What Does Ofcom Actually Require of VoIP Providers?

Under Ofcom's General Conditions, any provider allowing calls to ordinary phone numbers must also allow calls to 999 and 112, at no charge, regardless of whether the underlying service is a physical line or VoIP. This wasn't always the case — VoIP was historically treated differently from traditional phone lines, but the rules have applied equally for some time now.

Providers must also pass caller location information to the emergency services wherever it's technically feasible. This matters more for VoIP than it did for traditional landlines, because a VoIP number isn't tied to a single physical address the way an old copper line was. Emergency calling is just one part of a wider set of obligations VoIP providers and businesses need to meet — our guide to VoIP and regulatory compliance covers the rest.

Why Location Information Matters More with VoIP

A traditional landline number was permanently linked to one address, so the emergency services always knew exactly where a 999 call was coming from. VoIP numbers don't work that way by default — a user could, in theory, take their handset or softphone anywhere with an internet connection and still dial out on the same number.

This is why VoIP systems need location information configured deliberately, rather than assuming it works automatically the way an old landline did. Multi-site businesses in particular need each location's address correctly associated with the extensions or numbers used there, so a 999 call from any site routes to the right local emergency service with the right address attached.

What Happens During a Power Cut?

Because VoIP relies on power and an internet connection, a home landline's traditional ability to keep working during a power cut doesn't automatically apply. Ofcom's rules require providers to offer at least one hour of backup access to emergency services during a power outage, for customers identified as depending on the service — commonly through a battery backup unit or an alternative access method.

For most business premises, this is less of a day-to-day concern than it is for vulnerable residential customers, but it's still worth understanding what backup provision your system includes, particularly if your business handles anything safety-critical. Our guides on staying connected to VoIP during power outages and VoIP's role in business continuity and disaster recovery go into more detail on building genuine resilience, not just meeting the minimum requirement.

What Should Businesses Check When Setting Up a VoIP System?

• Is location information correctly set for every site, if you operate from more than one address?
• Do mobile or softphone users have accurate location settings, since these can be more prone to defaulting to a head office address rather than wherever the person actually is?
• Has emergency calling been tested, not just assumed to work because the rest of the system does?
• Do new starters and site moves get flagged so location data is kept up to date, rather than set once and forgotten?

These aren't difficult things to get right, but they're easy to overlook during a system rollout focused mainly on getting calling itself working. They sit alongside the wider set of phone system security and compliance features worth checking during any setup.

Whose Responsibility Is This — Yours or Your Provider's?

The regulatory obligation sits with the provider, who has to build 999 access and location reporting into the service. In practice, though, the accuracy of the location data attached to your specific extensions and sites is something only your business can confirm, since the provider doesn't automatically know when you open a new office or move someone to a different desk. It's a shared responsibility in that sense — the provider builds the capability, but keeping the details accurate depends on your business keeping them updated.

What About Teams Calling and Other Cloud Platforms?

The same underlying Ofcom requirements apply to Microsoft Teams Calling as to any other VoIP-based system — emergency calling still needs to be configured correctly, in Teams' case through location data set in the admin centre per user or per site. It's not switched on automatically just because Teams Phone is licensed, so it's worth checking deliberately during setup rather than assuming it works the same way a traditional desk phone always did.

This is worth getting right regardless of platform, particularly with the 2027 PSTN switch-off moving every remaining analogue and ISDN line onto digital alternatives — emergency calling compliance isn't something to leave until the migration itself is already underway.

Frequently Asked Questions

Do all VoIP systems support 999 calls? Any provider connecting calls to the standard phone network is required to support 999 and 112 calls. If you're ever unsure, it's worth confirming directly with your provider rather than assuming.

What happens if my internet goes down during an emergency? Without an internet connection, a standard VoIP call — including a 999 call — won't connect. This is why it's worth having a fallback plan, such as mobile phones on hand, for genuine emergencies, particularly at sites with unreliable connectivity.

Do I need to update location information every time someone moves desks? For fixed-site staff, location is usually set at a site level rather than per desk, so day-to-day desk moves don't typically need updating. Moving to a different office or site is what genuinely needs the location data refreshed.

Is this different for a small business with one office compared to a large multi-site organisation? The underlying requirement is the same, but the practical risk of getting it wrong is higher for multi-site businesses, since there's more location data to keep accurate across more locations.

Emergency calling is one of those things worth confirming rather than assuming. Request a quote if you'd like T2K to check your system's emergency calling setup, read our guide to what Microsoft Teams Calling is if you're comparing platforms, or use our PSTN switch-off checker if you're still planning a migration off traditional lines.