Question to the Department for Science, Innovation & Technology:

To ask the Secretary of State for Science, Innovation and Technology, what assessment she has made of the adequacy of existing contingency arrangements to ensure access to emergency services during prolonged power outages in areas affected by the Public Switched Telephone Network migration.

The Government is committed to ensuring any risks arising from the industry-led migration of the Public Switched Telephone Network (PSTN) to Voice over Internet Protocol (VoIP) are mitigated for all customers. No household should be left without means to contact emergency services in the event of a power cut following the PSTN migration.

In December 2023 and November 2024, major communication providers signed and agreed the safeguards in the PSTN Charter and Non-Voluntary Migrations Checklist, including providing vulnerable customers with free battery back-up devices for power cuts. Ofcom General Conditions state that these devices should last for a minimum of one hour, but in practice many providers issue units that provide 4-7 hours of battery life.

In December 2023, Ofcom launched a public Call for Input on the power back-up at mobile access sites. Ofcom published an update on this work in February 2025, confirming they are completing further analysis to determine the appropriate and proportionate measures that mobile operators should put in place.