What happens to your home phone during a power cut depends on the type of phone service you have.
With the move to Digital Voice, home phones now work very differently compared to traditional landlines.
Understanding the difference is important - especially for emergencies.
The simple answer
Traditional landlines often continue working during a power cut, but Digital Voice home phones usually stop unless there is backup power available.
This difference is due to how calls are delivered.
How traditional landlines worked during power cuts?
Old-style landlines:
- Used copper phone lines
- Carried their own electrical power
- Worked even if your home lost electricity
This made them reliable during outages - but the technology is now being phased out.
How Digital Voice works during a power cut?
Digital Voice home phones:
- Use your broadband connection
- Rely on your router being powered
- Stop working if there is no electricity
If your router or fibre equipment has no power, calls can't be made or received.
What about Full Fibre and Digital Voice together?
With Full Fibre:
- Fibre-optic cables carry data only
- They do not supply electrical power
- Your Optical Network Terminal (ONT) and router both need power
Without power, the phone service goes offline.
How long do phones stop working for?
Phones stop working:
- For the duration of the power cut
- Until power is restored to your equipment
Once power returns, services usually reconnect automatically within minutes.
Backup options during a power cut
There are ways to stay connected:
1️⃣ Battery backup units
- Keep your router and ONT powered
- Can last 1-4 hours, depending on capacity
- Suitable for short outages
Some providers offer these for vulnerable customers.
2️⃣ Mobile phones as backup
- Mobile networks usually remain active
- Smartphones provide an emergency option
- Keep devices charged where possible
This is the most common backup solution.
3️⃣ Uninterruptible Power Supply (UPS)
- Provides backup power to broadband equipment
- Can support longer outages
- Often used in home offices
This offers the most flexibility.
Do I need to take action?
You should consider backup power if:
- You rely heavily on your home phone
- You live in an area with frequent outages
- You don't have reliable mobile coverage
Planning ahead avoids surprises.
The key takeaway
During a power cut, traditional landlines may still work, but Digital Voice home phones usually stop unless you have backup power in place.
Having a mobile phone or battery backup ensures you stay connected when it matters most.