Telephone socket on full fibre
Updated: October 2026
The hub is on the wall, the phone lead is in the green port, and the bedroom socket has gone quiet. A telephone socket on full fibre is often the wrong purchase. Full fibre ends at the optical network terminal, and Digital Voice expects the phone in the router, not in the old extension plates. This is the stop check before any of the eight plates on the [telephone socket comparison](/hub/sockets-and-extension-leads/telephone-socket). It does not rank those plates. If a copper master is still in use, the fork is on [master or secondary telephone socket](/hub/sockets-and-extension-leads/telephone-socket/sub/telephone-socket-master-or-secondary).
The hub is on the wall, the phone lead is in the green port, and the bedroom socket has gone quiet. A telephone socket on full fibre is often the wrong purchase.
The hub is on the wall, the phone lead is in the green port, and the bedroom socket has gone quiet. A telephone socket on full fibre is often the wrong purchase. Full fibre ends at the optical network terminal, and Digital Voice expects the phone in the router, not in the old extension plates. This is the stop check before any of the eight plates on the telephone socket comparison. It does not rank those plates. If a copper master is still in use, the fork is on master or secondary telephone socket.
Our top picks
| Badge | Product | Role | On full fibre | Still a buy when | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  1STec NTE5c MK2 faceplate, tool-less IDC | NTE5c copper faceplate | Does not replace the optical terminal | A copper master is still the live line | 9.2 | about £9.95 | View offer |
| Alternative |  1STec 1STec 2/3A surface kit with IDC tool | 68 mm extension kit | Will not cover an optical terminal | A master is already on a copper line | 8.2 | about £8.95 | View offer |
| Best value |  British General BG white secondary, screw | Analogue secondary | Not supported on Digital Voice | The service still uses extension sockets | 8.8 | about £3.89 | View offer |
On this page
Two lines that look the same
Fibre to the cabinet still uses the copper pair into the house. The master stays in circuit, and a filter still matters unless that master is already filtered. Fibre to the premises ends at the optical network terminal, and the phone leaves from the router.
Openreach dates the closure of the old public network at 31 January 2027. GOV.UK uses the same date, and adds that some people without broadband may get an interim landline until a digital option or 2030, whichever is sooner. That interim is not a reason to buy a new extension for a house that already has a hub. Openreach’s new-sites guide says full-fibre builds do not get new analogue extensions.
If a copper master still feeds a filter and a modem, you are on the cabinet side. If an optical network terminal and a hub are the only live path, you are on the full-fibre side. These plates do not become fibre sockets because a bullet mentions broadband.
What happens to the old sockets
BT says extension sockets are not supported on Digital Voice. The phone goes in the hub’s phone port, or in a Digital Voice adapter where one was supplied. A new secondary does not bring a dead bedroom plate back. BT’s extension article also points at Home Phone Standard as a service that can still use extensions. If that name is on your bill, ask before you decide the plates are finished.
Your line moves when your provider migrates it. Until then, a working wall phone is still on the old path. After it, a quiet extension is a service change, not a missing £3.89 plate.
One review of B004TRRVA2 describes a BT-to-RJ11 lead from house wiring to the optical network terminal. That is one person’s setup, not a method this page recommends. For a handset in two rooms, a DECT phone with the hub is the route providers describe.
Alarms and the people who must be told
A telecare base should slow you down. Citizens Advice says you tell both the landline provider and the alarm provider, and that you should not be switched until they are confident the alarm works. A new master does not perform that test.
BT is specific about the port. A compatible telecare base goes in the hub’s phone port, not in the Digital Voice adapter. An adapter can be fine for a handset and wrong for the alarm. If a switch date is booked, make those two calls before you change the old master. The GOV.UK interim landline is for some customers without broadband.
When a socket from this comparison is still the right object
Buy a plate when the copper master is still the live line, on fibre to the cabinet or a traditional line that has not moved, and you are replacing a cracked front or adding a secondary the service still supports. The telephone socket buying guide is the next page, and how to fit a telephone socket is the sequence. Buy one as well if the provider has told you to reuse the master. Do not generalise that instruction to a house whose phone is already in the hub.
Do not buy a plate to chase broadband speed. None of the eight is clearly an MK4, and this file does not authenticate a genuine Openreach title. Do not buy a 68 mm kit to cover an optical network terminal. The wide case, full fibre with the phone in the router, is do not buy. A qualifying purchase can earn a commission at no extra cost to you. There was no lab test on a fibre line.
Common questions
Will a new secondary restore a Digital Voice bedroom phone?
No. BT says extension sockets are not supported on Digital Voice. The £3.89 screw plate and the £8.95 surface kit are both those sockets. Use the hub phone port, an adapter for an ordinary handset, or a DECT phone. Home Phone Standard is the exception BT still ties to extension wiring. Check that name on your bill.
Is the 2027 date real if the wall phone still works?
Openreach and GOV.UK both point at January 2027 for the industry switch-off. Your line moves when your provider migrates it, which can be earlier. A working wall phone means you are still on the old path. It does not make a new extension a good buy if the migration letter already names the hub.
Where does a care-alarm base go?
In the hub’s phone port, if the base is compatible, and not in a Digital Voice adapter. That split is BT’s instruction. Before the switch, tell the landline provider and the telecare provider, and ask for a test, which is the Citizens Advice guidance. A new wall socket does not complete those calls.
What is the difference between FTTC and FTTP here?
Fibre to the cabinet still uses the copper master, so a faceplate or a secondary can match a live line. Fibre to the premises uses the optical network terminal, so the old extensions are the wrong purchase. An optical terminal plus a hub means do not buy. A filtered copper master with a modem in the phone socket means you may still buy.
Can I reuse the old master for an analogue port?
Yes, if the provider tells you to. That is the exception, not the default on full fibre. Reuse the master they name, and do not add secondaries they will not support. One review describes a BT-to-RJ11 lead to an optical network terminal. Treat that as one buyer’s setup, not a plan.
Related pages
Sources
Public UK sources on the master socket, BS 6312, and the digital landline switch. Listings checked 16 October 2026. Prices on amazon.co.uk move.
- Openreach copper handbook (retrieved 16 October 2026)
- Openreach new-sites wiring, August 2024 (retrieved 16 October 2026)
- Openreach PSTN switch-off (retrieved 16 October 2026)
- GOV.UK telecommunications modernisation timeline (retrieved 16 October 2026)
- Ofcom, future of landline calls (retrieved 16 October 2026)
- Ofcom, broadband and landline faults (retrieved 16 October 2026)
- BSI BS 6312-1:1994 plugs (retrieved 16 October 2026)
- BT Digital Voice setup (retrieved 16 October 2026)