A small white T-shaped socket, commonly found behind furniture or in basements, is the last physical connection to copper telephone lines that stretch for several kilometers from a telephone central. These copper lines are being phased out across France, with the goal of completely removing them by 2030. As part of this transition, the T-shaped socket will be removed, along with any devices connected to it, such as old alarms, teleassistance systems, elevators, and payment terminals. Even in homes that have already switched to fiber-optic internet, these devices may still rely on copper lines to function. The copper network has historically carried both voice calls and ADSL internet service, using the same wire but different frequencies for each. The switch to fiber-optic technology happens in two stages: first, a commercial closure where no new copper-based subscriptions are sold, and second, a technical closure where the signal is cut for existing users. The commercial closure began in January 2024 for a small number of communes, then expanded to the majority of France in January 2026, with the remainder of the country following in January 2027. Orange, a major telecommunications provider, announced on January 27, 2026, that it had completed the technical closure of copper lines in 763 communes across 54 departments and 14 regions, affecting around 900,000 homes and businesses. Some 162 communes had begun the process as early as late 2025. However, for nearly 8,000 communes that are not yet sufficiently connected to fiber-optic networks, Orange has delayed the commercial closure to avoid leaving users without service, even in areas that are almost entirely fiber-connected. More than half of the remaining analog telephone lines used by businesses still support critical functions such as elevator alarms, surveillance systems, remote meter reading, and electronic payments. In response, the French Telecommunications Federation published a frequently asked questions (FAQ) guide in October 2025 to help users transition to fiber-compatible solutions. Alarm transmitters and teleassistance boxes rely on analog lines to send specific tones that monitoring centers can interpret. Plugging these into a fiber box can lead to misinterpretation or signal loss, as internet telephony converts voice into digital data packets that may not match the analog tones. Copper lines were powered from the telephone central, allowing them to function even if a subscriber's home lost power. In contrast, fiber-optic systems depend entirely on the home’s electrical supply, requiring backup batteries to keep operating during outages. To check if a home is still connected to copper, users can look for a T-shaped socket where the fixed telephone or a box is plugged in. A wall-mounted optical box with fiber entering it indicates that the switch to fiber has already occurred. Resources like Orange’s interactive map, the Ministry of Economy’s search tool, and the website treshautdebit.gouv.fr can help users find the specific deadline for their commune. Orange plans to give residents a three-year notice before implementing the technical closure in a commune, allowing time to prepare for the transition. Once the closure is complete, the copper cable may be removed or repurposed for the fiber network. The existing conduit that has run along streets for decades may be used to guide new fiber cables or be removed in future infrastructure work. This copper phase-out is happening alongside the gradual shutdown of 2G and 3G mobile networks. Missing these deadlines could leave some devices, such as alarm systems using 2G SIM cards, vulnerable to future service interruptions.