What actually switches off

The switch-off is often described as "landlines going digital", which understates it. Openreach is retiring the copper platform itself, so every product built on it goes at the same time:

• Analogue phone lines — single lines, multi-lines, and anything on Wholesale Line Rental.
• ISDN2 and ISDN30 — the digital circuits most on-premise phone systems still sit on.
• ADSL and FTTC broadband — these need a copper line underneath. When it goes, they go.
• Every device using a phone line for signalling — which is the part that catches people out.

The audit nobody does until it's late

Phones are the obvious part and usually the easiest to migrate. The difficult items are the ones nobody has thought about in fifteen years, because they were installed by a different contractor and have quietly worked ever since.

The practical method is unglamorous: walk the site, open the comms room, and trace every line on the bill to a physical thing. Most sites find at least one line nobody can account for — and it's usually attached to something that matters.

You may already be affected

The final date is 2027, but the restrictions started years ago. A national stop-sell came into force in September 2023, meaning legacy services can no longer be ordered and existing ones are effectively frozen. In practice that means no new analogue lines, no moving an old service to a new provider as-is, and limited ability to change what you have without upgrading.

Exchange-level stop-sells have been rolling out on top of that. By early 2026 they covered well over a thousand exchanges and many millions of premises, and the programme has continued since. If your site sits in a stopped exchange, some options have already closed.

Legacy line rental pricing has also been rising in stages through 2026, deliberately, to encourage migration. Waiting is no longer cost-neutral — it is actively more expensive than moving.

What happens if you do nothing

You will not simply keep your old service. Businesses that haven't migrated by the deadline are moved to a basic emergency fallback arrangement — enough to reach emergency services, not enough to run a business on. Inbound calls, call routing, broadband and anything else on the line stop behaving normally.

Openreach has been clear there won't be a single dramatic cut-off moment for everyone, as exchanges are being migrated in a phased programme. That is a reason to act sooner rather than later, not a reason to relax: your exchange may go well before the final date.

What replaces it

Is your network actually ready for it?

This is the part telecoms resellers tend to skip, because it isn't their trade. Moving voice onto your data network means the data network now carries calls — and a lot of sites we survey are not in a fit state for that.

• Cabling. Handsets need a data outlet at every desk position. Sites that once ran a separate voice cabling system often don't have enough data points where the phones need to be.
• PoE budget. IP handsets draw power over Ethernet. Adding thirty or forty of them to a switch that's already running access points and cameras can exceed the power budget.
• Switch capacity and VLANs. Voice wants its own VLAN and sensible quality-of-service settings, or calls degrade whenever someone runs a big backup.
• Internet resilience. Once voice runs over your connection, an outage takes the phones with it. A second connection or a mobile failover stops that being a crisis.
• Comms room condition. If the cabinet is a nest and nothing is labelled, every step of this project takes longer and costs more.

A sensible six-month plan

Six months is comfortable if you start now. It gets tight if the audit turns up a lift line and an alarm path that need third-party contractors, which it usually does — and everyone else's tight timescale is competing for the same engineers.