The PSTN switch-off: what it means for your phone lines

What is the PSTN switch-off?

The public switched telephone network (PSTN) is the analogue, copper-based network that has carried UK landline calls for decades. BT Group and its network business, Openreach, are closing it on 31 January 2027. From then on, landline calls on the Openreach network travel as data over a broadband or fibre connection.

The date has moved once already. The original target was December 2025, and it was later put back to January 2027. As of September 2026, Openreach says the 31 January 2027 deadline remains unchanged.

The closure was formally announced in 2017, and Openreach stopped selling new analogue lines nationally on 5 September 2023. Its latest estimate, published on 24 September 2026, is that around 1.2 million lines are still on the old network, including around 350,000 business premises. In February 2026 the figure was about 2.8 million.

What will stop working?

Anything that depends on an analogue or ISDN (integrated services digital network) line. Check each of these:

• analogue phone lines, and older phone systems connected to them;
• ISDN2 and ISDN30 lines, often used by on-site phone systems;
• intruder and fire alarms that signal over a phone line;
• lift emergency phones (in February 2026 Openreach counted more than 12,000 lift lines still to upgrade);
• card payment terminals that use a phone line;
• door entry systems, CCTV links and fax machines;
• ADSL broadband, and FTTC broadband that runs alongside an analogue line.

The last item catches people out. Some broadband depends on the analogue line underneath it, so it has to move as well, usually to SoGEA or full fibre.

What happens to lines that haven’t moved by the deadline?

Openreach has set up a last-resort service called Emergency Voice and Access Continuity (EVAc). From 31 January 2027, eligible lines that haven’t moved may be transferred to it so that essential calls still work. In its September 2026 update, Openreach added that it will also keep linked broadband running where technically possible, for business and residential customers.

Don’t plan around it. Openreach describes EVAc as temporary, limited and more expensive than digital alternatives. It can’t be ordered in advance, its capacity is limited, and it may not support the calling features you use today. Openreach also says single lines that can’t be moved onto EVAc will be ceased in stages.

The cost of standing still is rising too. Openreach is raising its wholesale rental for analogue lines in three steps during 2026. The last, on 1 October 2026, takes it to double the 2025 level. Your provider sets the price you pay, so check how these rises affect your contract.

What should you do now?

1. List every line. Check your bills for numbers nobody recognises. They may serve an alarm, a lift or a card machine.
2. Find out what each line does. Ask the supplier of each device whether it works on a digital line, needs an adapter or needs replacing. Openreach’s advice to businesses is to review, test, then switch.
3. Check your contracts. Note the end dates and notice periods for your lines, broadband and phone system.
4. Choose your replacement for calls, and for the connection they will run over.
5. Plan for power cuts and emergency calls. Decide which phones and routers need battery back-up, and tell your provider if anyone relies on a landline.
6. Book the move early, and port every number you want to keep.

What replaces analogue and ISDN lines?

There are two decisions to make: how your calls are handled, and the connection they travel over.

For calls, the main options are:

• Hosted VoIP (voice over internet protocol). The phone system runs in the cloud. Desk phones, softphone apps and mobiles connect over the internet, and adding a user doesn’t mean adding hardware in the office. Many hosted systems also work with Microsoft Teams.
• SIP trunks (session initiation protocol). If you have an on-site phone system that is still supported and can use SIP, SIP trunks replace your ISDN channels and connect it to the phone network over your data connection.

For the connection, the main options are:

• SoGEA (single order generic Ethernet access). Broadband over the existing copper from the street cabinet, without an analogue phone service. Openreach positions it as the digital line for places where full fibre isn’t available yet. Its fastest version offers up to 80Mbps download and 20Mbps upload.
• FTTP (fibre to the premises), usually called full fibre. Fibre runs all the way into the building, where it is available.
• A leased line, for sites that need capacity reserved for them and faster repairs. Our connectivity services cover the options in more detail.

How Enhanced Group can help

We design and support cloud-hosted VoIP phone systems for desk phones and mobiles, with Microsoft Teams integration, Outlook synchronisation, call recording, queuing and reporting. We also supply the connection underneath, from fibre broadband to leased lines, with backup failover options.

Two of our clients have already made the move. Sparrow Crane Hire replaced an analogue phone system with VoIP, running over a dedicated leased line with a backup failover connection. Leaping Lambs Nursery & Pre School replaced its ISDN lines with SoGEA fibre broadband and hosted telephony across its sites in the Bristol and Bath region.

To talk through your lines and the devices that depend on them, book a consultation or read about our voice services.