The 2027 PSTN Switch-Off Explained: What You Need to Know

The PSTN (Public Switched Telephone Network) switch-off is the UK's transition from traditional copper landlines to digital voice (VoIP) calls made over broadband. The full switch-off is planned for January 2027. This means all traditional landline calls will route through your broadband connection instead of the copper network. You will need a working broadband connection to make calls.

What Is the PSTN Switch-Off?

The Public Switched Telephone Network (PSTN) is the copper-wire system that has carried UK landline calls since the 1800s. BT and Openreach are switching it off by January 2027, replacing analogue voice services with Voice over IP (VoIP) — calls routed through your broadband connection instead of dedicated copper pairs. Over 2 million UK homes still rely on a traditional phone line without a broadband connection. The transition is closely linked to the nationwide rollout of full-fibre (FTTP) broadband, which now reaches 82% of UK premises. Openreach has already begun migrating exchanges area by area, with stop-sell orders preventing new PSTN connections in completed zones. All providers using the Openreach network — including Sky, Vodafone, TalkTalk and Plusnet — are affected by this change.

How Will It Affect Your Phone Line?

Your landline number stays the same — only the underlying technology carrying the call changes. Instead of a dedicated copper circuit, your handset plugs into a VoIP adapter or directly into your broadband router's phone port. BT calls this service Digital Voice; Sky and Vodafone offer similar digital-calling services included at no extra cost with their broadband packages. Call quality is generally equal to or better than analogue, with HD Voice available on compatible handsets. Most modern cordless DECT phones (available from £20) work fine with VoIP adapters. Older pulse-dial phones will not work and need replacing. If you want to keep your landline number, ensure your new provider supports number porting before you switch. The key practical difference: if your broadband goes down or there is a power cut, your phone will not work unless you have a mobile phone or a battery backup unit.

Impact on Telecare, Alarms and Special Equipment

This is the most critical concern around the PSTN switch-off. An estimated 1.5 million UK households use telecare pendants, monitored burglar alarms or health-monitoring devices that dial out over the copper phone line. These devices may fail over VoIP because of latency, packet loss or the absence of the line voltage that powers some older equipment. Contact your telecare or alarm provider now to check compatibility — do not wait until migration day. Most alarm companies offer GSM (mobile network) communicators as replacements, typically costing £50–£120 fitted. Openreach has paused migrations in areas with high numbers of vulnerable customers until solutions are confirmed. Providers must also offer priority fault repair (within 24 hours) for customers registered as vulnerable. In rural areas where FTTP is unavailable, alternative broadband types such as fixed wireless access or satellite may be used to support VoIP instead.

What You Need to Do to Prepare

First, check whether your local exchange has already been migrated — Openreach's online checker and your provider's website can both confirm this. If you are still on ADSL (speeds typically 10–17 Mbps), upgrading to fibre broadband is essential before the switch-off, since VoIP requires an active broadband connection to function. Test all connected equipment well in advance: plug your phone into the router's phone port, check your alarm panel's communication method, and verify telecare devices with their monitoring centre. Invest in a battery backup unit (an uninterruptible power supply, available from £40) if you rely on your phone during power cuts — unlike copper PSTN, VoIP needs mains electricity. Your provider should contact you at least 30 days before your area's migration date. If you have not heard anything by mid-2026, call them proactively. FTTP coverage stands at 82% and is rising steadily, so most areas can already access full-fibre broadband.

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Frequently Asked Questions

Will I lose my landline phone number?

No. You will keep your existing phone number. The change is in how calls are carried — from the copper network to your broadband connection using Digital Voice (VoIP) technology. Your number stays the same.

What do I need to do before the PSTN switch-off?

Ensure you have a working broadband connection. If you use a traditional landline phone, you will need a compatible handset or an adapter. Your provider will contact you to arrange the transition. Special provisions exist for vulnerable customers who depend on landlines.

Will the PSTN switch-off affect my broadband?

No. The switch-off only affects how voice calls are handled. Your broadband connection will continue to work as normal. In fact, the switch-off is accelerating the rollout of FTTP, which delivers faster broadband.

What about home alarms, medical devices and telecare?

Devices that rely on the copper phone line (burglar alarms, medical alert pendants, care alarms) will need upgrading or adapting. Contact your provider and device manufacturer well before the switch-off date to ensure continuity. Vulnerable households will receive additional support.

Related Guides

Fibre Broadband Explained: FTTP vs FTTC · Best Broadband for Rural Areas in the UK · Broadband Installation: What to Expect · Keep Landline · Types Of Broadband Uk

Methodology & Sources

Information in this guide is sourced from Ofcom market reports, Openreach coverage data, ISPreview.co.uk, provider websites and independent broadband research from Point Topic and Thinkbroadband. Prices and availability are checked monthly. Speed data reflects advertised average speeds from provider Key Facts documents.