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BT Smart Hub 3 connections

parrott_john — Sat, 29 Aug 2026 17:15:33 GMT

I have an undocumented green phone socket on my BT Smart Hub 3. Can I use this for a landline phone and how many phones could I connect?

Re: BT Smart Hub 3 connections

WSH — Sat, 29 Aug 2026 17:22:05 GMT

Yes & no.

Yes, it can be used with a landline phone but only if you have Digital Voice (DV) with BT. Not sure how many phones it would support but modern phones don't need the amount of current to ring that old phones did, so the idea of REN doesn't really apply anymore.

Re: BT Smart Hub 3 connections

licquorice — Sat, 29 Aug 2026 17:22:43 GMT

Yes, it is for the BT Digital Voice service. You can connect a number of phones, the exact number will depend on the phones.

Re: BT Smart Hub 3 connections

parrott_john — Sat, 29 Aug 2026 17:36:28 GMT

Thanks WSH. Yes I do have DV from BT. My old phones have batteries in them so presumably REN would have been irrelevant anyway. Any ideas about the connector I would have to use to connect to my old wired system (3 phones)

Re: BT Smart Hub 3 connections

WSH — Sat, 29 Aug 2026 17:46:31 GMT

By "wired system" do you mean the extensions in the house?

If so, then basically all you need to do is disconnect the extension wires to the master socket.* Get a lead with a BT phone plug to BT phone plug and use that to connect the nearest extension socket to the Smart Hub.

*If you are still on part fibre (FTTC/VDSL), you still need the incoming phone line, so don’t disconnect that from the master socket. Your internal extensions are your property, however.

Re: BT Smart Hub 3 connections

parrott_john — Sat, 29 Aug 2026 17:48:57 GMT

Thanks liquorice, that's what I thought but the BT man denied it. And it does indeed work with an old phone directly plugged in. But I wonder if I can connect to 3 other phones via the existing phone wiring?

Re: BT Smart Hub 3 connections

licquorice — Sat, 29 Aug 2026 17:51:20 GMT

Shouldn't be a problem, try it and see.