Calling 999 on a digital landline
In brief
- On digital voice, you cannot call 999 if the router has no power. No power means no phone.
- Your provider must offer at least one way to contact 999 during a power cut, typically a battery backup or a mobile solution.
- If you depend on the landline, ask your provider what they offer and register for the Priority Services Register.
How emergency calls work on digital landlines
On an old analogue phone line, a basic corded handset could sometimes make calls even during a power cut, because the line carried its own power. Digital voice services work differently. Your calls travel through your broadband router, which needs mains electricity.
If the power is off and the router has no backup power, you cannot make calls, including 999.
This is the single most important thing to understand about the move to digital landlines.
What your provider must do
Under General Condition A3, Ofcom requires phone providers to offer an emergency-calling solution to customers who:
- Rely solely on a landline (no reliable mobile signal at home), and
- Have told their provider they need it
The solution must allow access to 999 for at least one hour during a power cut. Providers typically offer one of:
- A battery backup unit for the router
- A mobile handset with basic credit for emergency use
- A hybrid adapter with mobile fallback
You may need to ask for this. Providers are not always proactive about offering it.
What you should do
1. Check whether you rely solely on a landline
Try making a mobile phone call from inside your home. If the call works reliably, you have a backup route to 999 during a power cut (as long as the phone is charged and the mobile network is up). If mobile signal is poor or absent, you may qualify for a free emergency-calling solution from your provider.
2. Tell your provider
Call your phone or broadband provider and say:
"I need to be able to call 999 during a power cut. Mobile signal at home is [poor / absent]. What backup solution do you offer?"
Ask them to note it on your account. If you are on the Priority Services Register, mention that too.
3. Understand the limits
The one-hour minimum is a regulatory baseline, not a guarantee. Longer outages are possible. Think about what you would do if both the landline and mobile were down for several hours:
- Is there a neighbour nearby who could help?
- Do you have a way to charge your mobile phone (power bank, car charger)?
- Is there someone who would check on you if they could not reach you?
Telecare and 999 are different
Telecare alarms (personal pendants, lifelines) do not usually dial 999 directly. They dial a monitoring centre, which then decides whether to call the emergency services. The emergency-calling backup from your phone provider covers 999 calls, but it does not guarantee your telecare alarm will work.
If you use telecare, you need to check the alarm's own signalling path and power resilience separately. See Telecare and personal alarms.