Openreach says about one million copper-based lines remain in the UK ahead of its Jan. 31, 2027, retirement of traditional phone service, with 300,000 at business premises where connected equipment may need migration.
Openreach, a BT Group subsidiary that operates the UK’s fixed network, gave the estimate in an Oct. 30 notice. In a July 31 update, it put the total at 1.5 million lines, including about 350,000 at business premises. The later notice does not explain the difference between the estimates.
The operator says business lines still support equipment such as card-payment systems, lift emergency phones, fire monitoring, security systems and building access controls. Businesses should check compatibility with equipment and service providers. Openreach says some sites may need hardware replaced or reconfigured, and that costs depend on the provider and services involved.
Customers still using the network after the cutoff may be transferred to a temporary emergency voice-only access service (EVAc) for essential calls. Openreach says access to the fallback is restricted and costs more than digital options. Its business guidance warns that some customers could lose service altogether.
Openreach says the network has become harder to maintain as equipment is no longer being made and spare parts dwindle. It estimates the PSTN is about 60% less reliable than its fiber networks. “Businesses and organisations that delay action are making things harder for themselves,” said James Lilley, Openreach’s director of All-IP.
Rental charges for Openreach’s Wholesale Line Rental products and legacy ISDN services doubled from their 2025 level on Oct. 1, the company said. It plans further increases from February 2027 but did not specify their size. Openreach also says it is offering communications providers free or discounted connections for some customer migrations.
The Office of Communications (Ofcom) counted 3.2 million residential landline customers using the PSTN in July 2025, compared with 5.2 million a year earlier. During the year to July 2025, 1.9 million residential customers moved to voice over internet protocol (VoIP), while just over one million households switched to broadband-only service. These figures cover residential customers at an earlier date, unlike Openreach’s later estimate of copper-based lines nationwide.
Separately, a European Commission proposal would require EU member states where copper networks remain in service after June 30, 2029, to submit transition plans by Oct. 31 that year. It would set Dec. 31, 2035, as the deadline for requiring copper shutdowns in covered areas, with an exception where fiber is not economically viable and no adequate replacement is available. The proposal remains under legislative review. Openreach’s planned PSTN retirement date in the UK is Jan. 31, 2027.
