The BT Openreach New NTE5C Master Socket (with the Mk4 frontplate) has been available for some time now. As I’m a telephone engineer, who has dealt with master sockets for years, I thought I’d give a guided tour

Before We Start…

If you don’t want to read my masterpiece below, and just need to get in touch, click here for the details.

Meanwhile, the whole issue of moving you master socket is dealt with here and here!

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To clarify, I’m looking at the type with the “Mk4”  filtered front plate (shown above). You can, however, obtain other front plates, which just have a BT phone-type socket.

What’s good?

Dealing with the older-style NTE5 sockets can be very fiddly!  Attachment of multiple extension wires (by punching down one on top of the other ) to the front detachable panel means accidental disconnection in some cases. There’s little room. Also, the screws can be lost!

However, there’s only one point of connection for extensions on the new filtered face plate. It’s of a push-down “cam-lock” type. Cramming in lots of wires is not possible  – they will need to be jointed elsewhere. Good!

Advanced Filtering.

Well, at least I hope so! Taking a filtered face plate apart reveals a complex set of filters.

Compare and contrast with the classic cheapie “dangle-filter” (on the right). Hopefully, this means more advanced filtration of noise, hence faster broadband. Apparently, it’s optimised for the fastest Openreach copper product.  This is fibre to the cabinet (FTTC) VDSL. I have seen this perform at almost 60Mb download. Astonishing!

April 2019 Update – See reader responses below. Some users report dramatic results.

July 2020 Update- Important!  Please note that the “pure” broadband output from the face plate is from the small socket on the front-plate (and the filtered “A” and “B” internal terminals directly behind it ) only. Put simply, if you wire an extension for a phone from it, then expect to get broadband via a plug-in filter, it won’t work!

Tool-less Installation.

It seems like Openreach want to get users to install the BT Openreach New NTE5C Master Socket themselves! For this reason, the wiring terminations are the “cam lock” type.

Simply poke wire in, and press down the lock. Done! You won’t even need a screwdriver for the front cover – it simply clips on (but not very well – more of this later.)


There seems to be a bit more inside the casing to route cables. Lack of space was a frequent problem with the older ones.

There’s an “A” and a “B” for a Remote Broadband Socket!

You can connect a socket dedicated to your broadband hub via a spare “A and B” pin, effectively delivering a “pure” broadband supply to wherever you need it.  This is before it gets chance to pick up interference from other devices. More about setting up a separate secondary data-only socket here

What’s Not So Good.
It’s a Bit Bulky!

This is the down-side of the better space inside.  With the filtered face plate, it sticks out around two to three inches from the surface.  It makes it vulnerable to impacts, and there’s not a lot to hold it on, which leads me on to…

It’s A Bit Lightweight!

The plastic lugs which keep the front look like they would harden and snap with time.  I can’t see an obvious way to repair it, apart from a foot of duct tape. In fitting them,I’ve occasionally had to bend the fastener mouldings to get a good engagement.  The old master sockets used to get bashed and occasionally crack, but they were a classic BT 1980’s solid design and highly resilient.

There’s not much hope for this one, unless you hide it from shoes, dogs, chair legs, aggressive turtles, high-speed RC cars, etc.   At least this generates repair work for me…

It Needs a Perfectly Level Surface to Attach To.

If your old master socket fitted onto a recessed steel back-box (as used by electrical outlets) flush-mounted in a plastered wall, you may find that the Mk4 filtered faceplate won’t stay on.  No, you’re not doing anything wrong – it’s just a poor design. It won’t cope with uneven surfaces. This utterly baffled me the first time it happened.  Fit it to a plastic, surface-mounted back-box, and it’s fine. However, this adds yet more protrusion and bulk.

The Cam Locks.

It actually took quite some effort to break the old-style punch-down connectors of a good-quality NTE5.  The new wire termination points may be tool-less, but once you’ve broken one (and it won’t be hard), you can throw the whole unit away.

The very early ones had red-coloured cam-locks. They did have the occasional fault.  The ones with clear plastic ones are more reliable.

The Cam Locks Again.

As per the comments above, you can only get one voice-side (telephone) extension pair (to a phone, etc) on the front cam locks.  So, if you need more, you’ll need to be clever in cabling and jointing, using three-way jelly crimps.  I have done this, and it takes time and thought.  In the old master sockets it was just about possible to punch down two or even three wires per pin.  Those days have gone. Buy a decent cordless set, such as a Panasonic, and run it from the front-plate!

And The Big Question – Will It Speed Up My Broadband?

If you are two miles from an exchange or FTTC cabinet, then it won’t move you closer. You will always suffer from slow speeds. Likewise, if there is a fault the Openreach network, or in your property, it won’t overcome it.

Update – June 2018 – many folks are reporting good results, included in the comments below.

But if you are in the mood to change your old NTE5, then it won’t do any harm.  The whole broadband thing constantly amazes me. I’m astounded that it ever works at all. I would suggest getting one.  I can even fit it for you (or find someone local who can) if you get in touch! !

Higher speed? The cynical old engineer in me says “maybe”. They are cheap-ish on eBay, and it’s worth a try. As I’ve said, some folks are reporting a marked speed improvement. For now, with the BT Openreach New NTE5C Master Socket, that’s about as far as I’d go.