The PSTN switch-off: what 31 January 2027 means for your business

This is for a business owner who keeps hearing that the old phone network is being switched off and wants to know whether it actually affects them, when, and what it costs to ignore. No sales pressure, just the dates and the practical consequences.

The short version

The Public Switched Telephone Network, or PSTN, is the traditional analogue phone network. BT Group is retiring it on 31 January 2027. Openreach is withdrawing every product that depends on it, grouped together under the term Wholesale Line Rental, or WLR. That includes ordinary analogue lines and ISDN.

If your business still has an analogue line, an ISDN circuit, or broadband that rides on top of one, you need a plan before then. As of the end of July 2026, Openreach reckoned around 1.5 million lines were still on the old network, including roughly 350,000 business premises. A lot of businesses have left this late, and the remaining window is short.

Has the date moved before? Yes, but not again

Fair question, because the switch-off was originally set for 31 December 2025 and was pushed back by 13 months. That history has made some people assume it will slip again.

Openreach has been explicit that it will not. It says the technical barriers to migration, including the protections needed for vulnerable telecare users, have been resolved, so the deadline is locked and the focus has moved to withdrawing the legacy products. Openreach's director for All-IP has said plainly that this time the deadline is final. Planning on another extension is not a strategy.

Staying put is already the expensive option

You do not have to wait until 2027 to feel this. Openreach has been raising the rental price of legacy WLR lines in steps to push migration along:

• 1 April 2026, prices rose by 20 per cent.
• 1 July 2026, a further 40 per cent.
• 1 October 2026, another 40 per cent.

The combined effect is roughly double the 2025 rental cost. Openreach has pointed out that in some cases it is already cheaper to be on a modern all-IP service than to stay on an old line. So the sum is not "cheap old line versus expensive new system". Increasingly it is the other way round, and the gap widens again in October.

Why you might not be able to simply switch provider

There has been a UK-wide stop sell on WLR since 5 September 2023, and it runs until the products are withdrawn in January 2027. In plain terms, no new analogue lines can be supplied anywhere in the UK. It also covers broadband products delivered over a WLR line, so there are no new lines, no analogue-to-analogue moves, and no switching an affected broadband service across to another provider exactly as it is.

There is a second rule on top of that. Where an Openreach exchange passes 75 per cent full-fibre coverage, an FTTP Priority Exchange stop sell applies. At those premises, full fibre becomes the only thing that can be ordered, and analogue lines, ISDN, FTTC and SOGEA all come off the menu. Openreach publishes these in tranches. Tranche 25, published on 27 July 2026, covered 112 exchange areas and nearly 555,000 premises, with the stop sell taking effect on 20 August 2027.

Worth being clear about what a stop sell does and does not do. It closes the door on new orders. It does not disconnect a line that is already working, so an existing service continues until you move it or the product is formally withdrawn. The practical sting is that your options narrow before your deadline arrives.

It is not only the phones

This is the part that catches businesses out. Anything that quietly dials out over a copper line is affected, not just the handsets on desks:

• Analogue phone lines, and ISDN2e and ISDN30e circuits.
• ADSL and FTTC broadband that sits on an analogue line.
• Intruder and fire alarm panels and diallers that call an alarm receiving centre.
• Lift emergency phones, intercoms and door entry systems.
• Card payment terminals, fax machines, franking machines and older EPOS links.
• Modems, building management systems and remote plant monitoring.

A working alarm or lift phone is a safety and insurance issue, not an IT preference. If you have not been through the building with a list, our step-by-step phone line switch-off guide walks through how to audit every connected device and migrate them in a sensible order.

The safety nets, and why they are not a plan

Two things exist for businesses that run out of time, and neither is somewhere you want to be.

Emergency Voice. Openreach is launching this at the end of January 2027 as a safety net for lines still connected at the deadline. It is voice only, and availability depends on BT's capacity at your exchange, so it is not guaranteed. That is a fallback for a failure, not a migration option you can rely on.

SOTAP. Openreach's single order transitional access products separate broadband from the voice product, so DSL broadband can run over a line without WLR underneath it. It is genuinely useful for premises where full fibre is not there yet, but the name gives the game away. It is transitional. It also becomes unavailable where an FTTP priority stop sell is in force.

What replaces it, in practice

For most small businesses the answer is two separate things that used to be bundled into one line. Broadband moves to SOGEA over the existing copper pair, or better, to full fibre. Calls move to a VoIP phone system, which keeps your existing numbers and usually costs less per month than the lines it replaces. Openreach expects around 15 million lines to end up on SOGEA and FTTP through this programme.

Two things genuinely need thinking about rather than glossing over. First, a digital phone service depends on your broadband and your power, so consider battery backup and how mobile calls are handled if the connection drops. Second, check that your connection can carry it, which our business broadband guide covers. If you are choosing a system, our comparison of the best business phone systems for UK small businesses is a sensible starting point.

What to do next

Start with an audit, because you cannot plan around devices you have not found. Walk the building, list every line and everything that dials out, and get written confirmation from each supplier about what replaces it. Then move in a controlled order, with alarms and lift lines tested rather than assumed.

If you would rather someone else did the legwork, get in touch for a free, no-obligation chat. We handle switch-off migrations, business phone systems and connectivity for businesses across Bury, Greater Manchester and Lancashire, and we will tell you straight if you have nothing to worry about.