• Openreach says about 350,000 business premises are among the remaining PSTN lines ahead of the 31 January 2027 retirement
  • A Community Fibre survey found 53% of unmigrated respondents had taken no action and only 12% had checked whether their equipment would still work

The fact

Openreach estimates that about 1.5 million lines are still operating on the UK's old Public Switched Telephone Network, including around 350,000 business premises. BT plans to retire the PSTN on 31 January 2027, along with the Openreach wholesale services that rely on it. Customers using traditional landlines are being moved to digital alternatives such as Voice over Internet Protocol. Some business lines also support payment terminals, lift alarms, security systems and other equipment, making their migration more involved than replacing a telephone service.

A Community Fibre survey of 2,000 people found that 45% of those who had not migrated were not confident about making the change. Among that group, 53% had taken no action and 12% had checked whether their equipment would continue to work. Community Fibre is a broadband provider promoting full-fibre services, so the findings represent its survey rather than official national migration data.

The assessment

The last stage of the PSTN switch-off is less about building new network infrastructure and more about moving the customers who are still using the old system. Providers need to contact those customers, arrange a digital replacement and check whether any equipment connected to the line will still work after the move.

Some of the remaining cases will take more work than others. Ofcom has said that later migrations are likely to include more customers with complicated needs because many simpler lines have already been moved. A line used for telecare, a lift alarm or another important device may need extra checks before it can be switched safely.

For BTW readers, the key issue is no longer simply how many PSTN lines remain. It is whether providers can identify and migrate the harder cases before the January deadline without interrupting services that still depend on the old network.

What to watch

Watch Openreach's remaining PSTN line count, particularly the number of business and harder-to-migrate connections still active as January approaches. Provider disclosures on telecare and other equipment-dependent lines will show whether complex migrations are keeping pace. Ofcom complaints, enforcement action or any change to the 31 January deadline would provide further evidence on how the final stage is progressing.