PSTN switch-off 2027: what to do now
The UK’s old copper phone network is being switched off. Phone lines, and anything else still plugged into them, need to move to a digital service first. Here’s what that means for your business, what to check, and how to avoid a last-minute scramble.
31 Jan 2027
BT switches off the PSTN and ISDN networks for good.
Source: BT
Months
to go. Audits, orders and installs all take time, so start early.
Not just phones
Alarms, lift lines, card machines and door entry often use the same lines.
Source: BT
What’s actually switching off?
The PSTN (public switched telephone network) is the copper network that has carried UK phone calls for decades. ISDN is the digital version many businesses use for multi-line phone systems. Both run on equipment that is ageing and harder to keep running.
After the switch-off, calls travel over broadband instead. For most businesses that means either a digital phone line from your broadband provider or a cloud phone system. Either way, every site needs a reliable internet connection, because that is now what your phones depend on.
New analogue and ISDN lines are no longer sold, and providers are already moving customers across. If you haven’t been contacted yet, you will be. It is better to plan the move yourself than to have a provider plan it for you.
In plain English
Before: phone line in the wall, calls over copper.
After: calls over your broadband, either through a digital line or a cloud phone system.
Your job: find everything that uses the old lines, choose what replaces them, and move before the date.
It’s not just your phones
The lines most often forgotten are the ones with no handset on the end. Check each of these at every site.
Intruder and fire alarms
Monitored alarms often signal over a phone line. Ask your alarm company whether yours has a digital or 4G route.
Lift emergency phones
Lift lines must keep working. Your lift maintenance company should confirm the upgrade and test it.
Card machines
Older payment terminals dial out over a phone line. Most modern ones use broadband, Wi-Fi or mobile data.
Door entry and gates
Intercoms and gate systems that call a phone number may need a new unit or a mobile connection.
Fax and franking machines
Often forgotten until they stop. Decide whether you still need them, and if so, how they will connect.
Telecare and lone-worker alarms
Anything that summons help needs extra care, including a plan for power cuts.
CCTV and building systems
Remote monitoring, heating and building management systems sometimes use a dial-up line.
Phone systems on ISDN
Older on-site phone systems connected by ISDN need a new connection or a replacement system.
Broadband tied to a phone line
Some broadband is sold with line rental. It moves to a broadband-only product, which can change the price.
Your switch-off checklist
Eight steps, in the order we work through them with clients.
List every line
Get a full list of your numbers and lines from your provider or bill, site by site. It’s common to find lines nobody knew they were paying for.
Find out what each line does
Match every line to a phone, alarm, lift, card machine or other device. Cancel the ones nobody uses.
Check your contracts
Note end dates and notice periods, so the move fits your contracts rather than the other way round.
Ask each device supplier
Get written confirmation that alarms, lifts and other systems will work on a digital line, and what it costs to upgrade them.
Plan for power cuts
Digital lines need power at your site. Decide which lines must keep working in a power cut and put backup power in place for them.
Check broadband at every site
Make sure each connection can carry voice reliably, and consider a backup connection where calls are critical.
Choose what replaces your lines
A like-for-like digital line, or a cloud phone system that also improves how your people work. Compare before you commit.
Keep your numbers and test
Move (port) your numbers across, test alarms and lifts after the change, and keep the old service until everything is proven.
How we help you through it
We start with an audit of your lines, devices and contracts, usually as part of our on-site technology healthcheck. Then we compare replacements from our network of more than 350 providers, negotiate the contracts and plan the cut-over site by site, so nothing is left on a line that is about to disappear.
Our advice costs you nothing. If you buy through us, the provider you choose pays us a fee, on the same basis whichever provider on the shortlist you pick. And if your current provider’s offer is the right one, we’ll tell you.
Questions we’re often asked
Do we have to do anything?
Yes, if you still have analogue or ISDN lines. Your provider will move you eventually, but that may not suit your contracts, your devices or your timing. Planning it yourself avoids surprises.
Will our phone numbers change?
No. You can keep your numbers. They are moved (ported) to the new service, and we plan the timing so calls keep flowing on the day.
We are in the middle of a contract. What then?
Check the end date and notice period first. Many providers will move you to a digital service within your contract, but it is worth comparing the market before you sign anything new.
What happens in a power cut?
Digital lines need power at your premises, so phones may stop working in a power cut unless you have backup power. Ofcom expects providers to offer at-risk customers a way to call 999 for at least an hour, but businesses should plan their own backup for critical lines.
Will our alarms and lifts still work?
Only if they are upgraded or confirmed as compatible. Ask your alarm and lift companies in writing, and test after the switch.
Is this a chance to improve our phones?
Often, yes. Moving to a cloud phone system can bring features like working from anywhere, call recording and Microsoft Teams calling. We compare both routes so you only pay for what you need.