PSTN Switch-Off 2027: What UK Businesses Need to Do Before 31 January

On 31 January 2027 BT retires the Public Switched Telephone Network, the copper phone network that has carried UK landline calls for over a century. On the same day Openreach withdraws Wholesale Line Rental, the product almost every traditional business line is built on. After that date an analogue line does not degrade or get more expensive. It stops.

Openreach has been blunt about it. In July 2026 its director of All-IP, James Lilley, said: "The PSTN switch-off is now just six months away and there is no extension to the deadline."

This guide covers what is being switched off, what in your building depends on it without you knowing, and the order to do things in.

Where things stand

• About 1.5 million lines were still on the old network at the end of July 2026, according to Openreach, including around 350,000 business premises. That is down from 2.8 million in February, so the queue is moving, but it is a long queue.
• No new analogue lines have been sold anywhere in the UK since 5 September 2023. Under the stop sell you also cannot change or move an existing one.
• Wholesale prices have doubled. Openreach raised the rental on legacy lines by 20% in April 2026, 40% in July and a further 40% in October, taking it to twice the 2025 rate. Providers are passing that on, so staying put is already costing more.
• In Scotland, Openreach figures published in September 2026 showed 39,132 lines still to move in Edinburgh and 30,653 in Glasgow, roughly one line in ten in each city.

The date has moved once already, from December 2025, to give providers time to protect telecare users. Do not plan on it moving again.

What actually stops working

The phone on the desk is the obvious one. The problem is everything else that was plugged into a phone socket years ago and forgotten.

What you have	Why it is affected	What replaces it
Analogue business lines	They run on the PSTN	Hosted phone system, Teams Phone or a single cloud line
ISDN2 and ISDN30	Withdrawn on the same date	SIP trunks or a hosted system
Broadband on a phone line (ADSL or FTTC)	The broadband rides on the line being withdrawn	SOGEA or full fibre, which need no phone line
Intruder and fire alarm signalling	Diallers call the monitoring centre over the line	IP or mobile signalling, fitted by your alarm company
Lift emergency phones	The alarm button dials out over an analogue line	A mobile or IP unit, fitted by your lift maintainer
Card machines	Older terminals dial up to authorise payments	An IP, wifi or mobile terminal from your provider
Door entry and gate intercoms	Many ring a handset or number over the line	An IP or mobile unit
Fax and franking machines	They dial over an analogue line	Online fax, or an adaptor if the device supports it
Telecare and lone-worker alarms	Pendant alarms dial out over the line	A digital unit from the telecare provider

Lifts deserve a specific mention. Openreach counted more than 12,000 lines serving lift alarms earlier this year. A lift must have a working two-way emergency phone, so a lift whose line has gone dead is not just inconvenient, it is out of compliance.

Your broadband is probably part of this

This is the one that catches people out. If your broadband was installed more than a few years ago, it is very likely delivered over the same copper pair as a phone line, and you pay line rental for a number nobody dials. When the line is withdrawn, the broadband goes with it.

The replacement is either full fibre, where it is available, or SOGEA, which is the same fibre-to-the-cabinet broadband without the phone line underneath. Both need to be ordered, and full fibre needs an engineer visit. Check this before you choose a phone system, because every modern phone system runs over your internet connection.

What to replace your lines with

For most businesses there are three sensible landing places:

• A single cloud line, such as Gamma PhoneLine+. Right for a sole trader, a shop or a small practice that needs one or two numbers and no call routing.
• Microsoft Teams Phone. If you already live in Microsoft 365, your number moves into Teams and rings on your laptop, mobile and desk phone. Our Teams Phone guide covers licensing and current prices.
• A hosted phone system such as 3CX. Right when you need call queues, a busy reception or a high volume of calls.

In all three cases you keep your number. It is ported from the old line to the new service, usually within one to two weeks.

Power cuts are different now

An analogue phone took its power from the exchange, so it worked in a power cut. A digital line runs through your router, and when the power goes, so does the phone.

Ofcom requires providers to give at-risk residential customers a free backup that lasts at least an hour. Businesses are expected to make their own arrangements. In practice that means a small battery backup on the router and any desk phone you rely on, and mobile apps for everyone else. If your alarm or lift now signals over the internet, the same backup needs to cover that too.

Do not rely on the fallback

Openreach is piloting a temporary service called Emergency Voice Access for lines that have not moved by the deadline. It is voice only, with no broadband and limited features, and it is aimed at residential lines. It is a safety net for vulnerable households, not a plan for a business.

The order to do it in

This month

1. Pull twelve months of phone bills and list every line and number you pay for. Most businesses find at least one they cannot explain.
2. Walk the building and find what each unexplained line is connected to: the alarm panel, the lift, the card machine, the franking machine, the gate.
3. Check what your broadband runs on. If the bill shows line rental, it is on the old network.

By the end of November

4. Call your alarm company and lift maintainer. They have the longest lead times, and they are fielding these calls from everyone.
5. Order the new broadband, if you need it, before anything else.
6. Choose the replacement phone service and set it up alongside the old one.

Before Christmas

7. Port your numbers. Do it while both services are running, so nothing is lost if a port slips.
8. Test everything end to end, including a call to the alarm monitoring centre and a card payment.
9. Cancel the old lines once the ports complete.

January is the worst month to start. Number ports and engineer visits take weeks, and every provider in the country will be working through the same backlog.

How we help

We run this as a fixed project for businesses across West Lothian, Edinburgh, Glasgow and the rest of the UK: the line audit, the broadband order, the new phone system, the number ports and the liaison with your alarm and lift contractors. If you are not sure what you have, get in touch and we will start with the audit. More on our business phone systems.

Sources

• Openreach, six months left before the UK's old phone network is switched off, 31 July 2026
• Openreach, time for a "big switch-up" as PSTN switch-off looms, 5 February 2026
• Openreach, stop sell and WLR withdrawal
• Ofcom, the future of landline calls
• GOV.UK, UK transition from analogue to digital landlines
• ISPreview, Openreach list UK cities with most analogue phone lines yet to make digital switch, September 2026