The PSTN deadline that matters for small firms is April, not 2027

Openreach used its 5 February 2026 announcement to tell British businesses that the copper phone network has 12 months left. BT Group will retire the public switched telephone network (PSTN) by 31 January 2027, and Openreach says all technical barriers to migration, including protections for telecare users, have been resolved. The deadline, in its words, is locked.

The number that matters for business is in the second half of the release. Of roughly 2.8 million lines still on the PSTN, more than half a million serve business premises. Those lines sit on Wholesale Line Rental (WLR), the family of legacy products Openreach is withdrawing, and their price is about to climb: up 20% on 1 April 2026, a further 40% on 1 July and a final 40% on 1 October, which Openreach says effectively doubles rental compared with 2025 rates.

James Lilley, director of all-IP at Openreach, put the logic plainly: “We are passing those costs on to providers who continue to sell legacy products.” He added a line aimed straight at the customer: “If your provider hasn’t contacted you, you need to ask why.”

That sentence is the real story. The switch-off date has been the headline for years, but the deadline that now matters for a small business is 1 April. From then on, every month on copper costs more, and the bill arrives through a provider that has not moved. The PSTN migration has stopped being an engineering project and become a supplier-management problem, and it is the customer who needs to manage it.

The laggards outside the big names

Openreach is careful about where it thinks the stragglers are. Many communications providers have already migrated much of their base, the release says, but “a number of smaller or specialist providers have been slower to act”. Lilley went further: “Most major Communications Providers moved their customers to digital long ago.”

The implication, which Openreach does not spell out, is that the risk sits wherever customers buy from local resellers and specialist suppliers – and that is how plenty of small and mid-sized firms buy everything from alarm monitoring to card terminals. If that is right, it suggests where the remaining half a million business lines are likely to be, and why a national price signal aimed at providers may take longer to reach the customer than Openreach would like.

There is also a timing trap. Openreach stopped selling WLR nationwide in 2023, as The Register pointed out in its report on the price rises. A business still on a WLR line in 2026 has therefore kept a product that could not be bought new for at least two years. The price rises are designed to end that inertia. Whether they end it at the provider or simply pass through to the invoice depends on contracts most small firms have not read.

The line nobody listed

The second risk is less visible than the phone on the desk. Openreach lists fire and burglar alarms and payment terminals among the equipment that will need to be migrated, and says the latest data shows more than 12,000 lift lines and around 500 lines serving closed-circuit television (CCTV) networks still need to be upgraded. Those circuits are easy to miss on an IT asset register, because they tend to belong to facilities, to the alarm company or to whoever installed the card machine.

Openreach’s own advice reflects that. It asks businesses to review their connectivity estate for anything still relying on the PSTN, to test equipment for free at its test labs, and then to switch. Its note on reviewing assets is blunt: “If you are unsure, contact your service provider; do not assume you are safe.”

A buyer’s checklist before April

For a CIO or the person who buys connectivity in a mid-sized firm, the practical sequence is short. Ask every provider that bills a line, in writing, which of the firm’s services are on WLR or other PSTN-based products and on what date each will move. Include the alarm, lift, CCTV and payment suppliers, not just the telecoms account. Check the contract for how wholesale price rises are passed through. Then book the testing early, because demand for Openreach’s free test labs is likely to rise as October approaches.

There is a commercial upside for those who move first. Openreach says it has offered special pricing on migrations to Single Order Generic Ethernet Access (SOGEA), its broadband product without a traditional phone service, and that in some cases it is already cheaper to be on all-IP products than to stay on WLR. A business that migrates before 1 April avoids every one of the three rises. One that waits for the January deadline pays all of them first.

Openreach has spent years saying the switch-off is coming. Its message now is about money, not dates: the cost of copper is rising, and it lands on whoever is still holding the line.