The switch to digital landlines

By January 2027, landline telephone services in the UK will switch to a fully digital network. The existing network, called the Public Switched Telephone Network (PSTN), will be withdrawn. The PSTN is an aging network that is becoming harder and more expensive to maintain. Calls will be carried over the broadband network instead.

The withdrawal of the PSTN is industry-led. It is not the direct result of government policy, although the government supports it. Decisions on migrating customers are made by the companies that operate and provide services on the network. The government says its role is to work with the industry “to ensure all sectors of the economy are protected, prepared, and upgraded safely”.

Customers are already being ‘migrated’ off the PSTN. Ofcom, the UK telecoms regulator, reports that the number of landline customers on the PSTN fell from 5.2 million in July 2024 to 3.2 million in July 2025. Ofcom expects that most customers will see minimal disruption from this process.

The industry had originally targeted a switch-off date of 31 December 2025. However, the migration of customers has been ‘paused’ twice in response to concerns raised about the impact on customers who rely on landlines or other devices that use the PSTN, such as telecare alarms.

Unlike traditional landlines, digital phone lines will not work in a power cut at the customer’s property because they connect to the customer’s internet. Ofcom requires phone providers to take measures to ensure uninterrupted access to emergency services for at least an hour, including during a power cut. This could include, for example, a battery supply or mobile phone. BT paused its rollout of Digital Voice for over a year from March 2022, in part because lengthy power cuts caused by storms in winter 2021/22 brought this issue “into sharper focus”.

Devices that rely on the PSTN include some telecare devices such as fall alarms. The government revealed in December 2023 that it had asked the industry to pause the rollout again following reports of “serious incidents” involving telecare devices.

Commitments to protect vulnerable customers

Phone providers subsequently signed up to a set of commitments to “protect vulnerable customers as phone lines are upgraded to a new digital network”. Under the PSTN Charter, providers agreed to, for example, not migrate users of telecare devices unless their device is compatible with digital landlines, and to provide battery back-up solutions that “go beyond” Ofcom’s minimum requirements.

Openreach (which owns the largest PSTN landline network) says these technical barriers to migration have now been resolved, so the January 2027 date is “locked in”.

Ofcom’s website provides more information for consumers on frequently asked questions about upgrading landlines to digital technology.