- Openreach is responsible for the network from the exchange or cabinet up to and including the master socket, the Network Termination Equipment (NTE), on your wall.
- The customer is responsible for everything on the inside of the master socket: extension wiring, secondary sockets, filters and handsets.
- Residential customers cannot contact Openreach directly; faults are reported to your phone or broadband provider, who raises them with Openreach.
- If a fault is found to lie in your own internal wiring or equipment, an engineer visit can be chargeable, so it pays to test at the master socket first.
- Openreach is migrating the network to all-IP under its published programme, with the legacy PSTN being withdrawn as the migration completes in 2027.
Openreach is responsible up to the master socket; the customer is responsible for wiring and equipment inside the home. Report all line faults to your provider, who decides whether an Openreach engineer is needed.
Last reviewed: June 2026
The master socket is the dividing line
Almost every dispute about who fixes a phone line comes down to one piece of plastic on your wall: the master socket, known formally as the Network Termination Equipment or NTE. This socket is the demarcation point between the Openreach network and your own home. The line running from the street, whether overhead or underground, terminates at this socket, and that point marks the end of Openreach's responsibility and the start of yours. The boundary is not a matter of convenience or local custom; it is the standard industry definition of where the regulated access network ends and private property begins.
Understanding this boundary saves money and time. If a fault sits on the Openreach side of the master socket, it is a network fault that Openreach repairs at no charge through your provider. If the fault sits on your side, in extension wiring or a faulty handset, it is your responsibility, and an engineer sent to find no network fault can leave you with a charge. Knowing which side of the line your problem sits on is the most useful diagnostic step you can take.
The modern master socket usually has two parts: a fixed lower section wired to the incoming line, and a removable faceplate that carries the customer's own connections. The split between these two parts is deliberate. The lower section is the network operator's territory, and the faceplate, along with everything plugged into it, belongs to the household. Recognising those two halves on your own wall makes the abstract idea of a demarcation point concrete, because you can physically see where one party's responsibility stops and the other's begins.
What Openreach is responsible for
Openreach owns and maintains the physical access network: the exchange equipment, the underground and overhead cabling, the green street cabinets, the drop wire that runs to your house and the master socket itself. If a tree brings down the overhead line, if the underground cable is cut during roadworks, or if the master socket is faulty, that is Openreach's responsibility. These are network faults, and you do not pay for their repair because the equipment belongs to Openreach.
Importantly, Openreach does not sell directly to residential customers and does not take fault reports from them. The company works behind the scenes for the phone and broadband providers who resell its network. That is why a person with a dead line phones their provider, not Openreach. The provider tests the line, and if the test points to a network fault, the provider books an Openreach engineer. The repair is coordinated through that provider relationship rather than directly with you.
This wholesale structure exists because Openreach operates as a functionally separate part of the BT Group, providing the same network access to every retail provider on equal terms. The arrangement is why a customer of one provider and a neighbour with a different provider both rely on the same underlying cabling and the same engineers. It also explains why your provider, not the network operator, is the party that carries the obligations to you: the contract, the repair timescales and any compensation all sit with the company you actually pay. Openreach's duty is to that provider, and the provider's duty is to you.
What the customer is responsible for
On the customer side of the master socket, responsibility shifts entirely to the householder. This covers the test socket behind the faceplate, any extension sockets you have had fitted, the internal cabling between them, microfilters, and the handsets, cordless base units and answerphones plugged in. If an extension socket works loose, a pet chews through a cable or a handset stops working, that is yours to repair or replace. None of this is an Openreach matter.
The practical test is the master socket itself. Most master sockets have a removable faceplate with a test socket behind it. Plugging a known-working phone directly into that test socket bypasses all your internal wiring. If the line works in the test socket but not at an extension, the fault is in your own wiring, not the network. If it fails even in the test socket, the fault is likely on the Openreach side, and your provider should treat it as a network fault.
Internal extension wiring is a common source of trouble because it is often old, hidden behind skirting boards and added by previous occupants without any record. Corroded connections, staples driven through a cable, or a faulty extension faceplate can all degrade a line or stop it entirely while the network itself is perfectly healthy. Because this wiring belongs to the household, replacing or rewiring it is a private job, and a customer is free to do it themselves or to hire an independent telecoms contractor rather than waiting on a network engineer. The same applies to handsets: a cordless base unit with a flat backup battery or a handset with a damaged cable will fail in ways that have nothing to do with the line outside.
Phone line fault responsibility by location
The table below maps common fault locations to the responsible party and the first point of contact. Use it to work out who should be fixing a given problem before you make any call.
| Fault location | Responsible party | Who to contact |
|---|---|---|
| Overhead drop wire to house | Openreach | Your provider |
| Street cabinet or underground cable | Openreach | Your provider |
| Master socket (NTE) | Openreach | Your provider |
| Extension sockets and internal wiring | Customer | You or an engineer you arrange |
| Handsets and base units | Customer | Replace or repair yourself |
How to report a fault and avoid charges
Reporting a fault correctly protects you from unnecessary charges. Before calling, plug a phone you know works into the test socket behind the master socket faceplate. If the line is fine there, the problem is your internal wiring and there is no need to involve the network. If it fails at the test socket, report it to your provider with that information, because telling them you have already tested at the master socket speeds up diagnosis and supports the case that it is a network fault.
Providers can charge for an engineer visit if the fault turns out to lie in your own wiring or equipment rather than the network. The charge typically applies when an engineer attends, finds the network healthy and identifies the issue as customer-side. Doing the test-socket check first is the single most reliable way to avoid this. Keep a note of the date you reported the fault and any reference number, because that record matters if you later make an automatic compensation claim for slow repair.
When you call, describe the symptoms precisely rather than in general terms. A line that is completely dead, a line with a constant hum or crackle, and a line that drops only in wet weather each point the provider's diagnostics in a different direction, and the crackle-in-the-rain pattern in particular is a classic sign of water tracking into an external joint, which is firmly an Openreach matter. Removing the faceplate and testing in the socket beneath it, then reporting the result, lets the provider run its remote line test against a known starting point. That combination of a clear symptom description and a completed test-socket check is what separates a fault that is fixed quickly at no cost from one that drifts into a chargeable, inconclusive visit.
Where compensation fits in
If the fault is a network problem and your provider does not repair it within the relevant timescales, Ofcom's automatic compensation scheme may apply where your provider is signed up to it. The scheme is designed so that eligible customers receive set amounts for delayed repairs without having to ask. It does not apply where the fault is on your own internal wiring, because that is not the provider's or Openreach's responsibility to fix.
This is another reason the master socket boundary matters so much. Compensation, free repairs and provider obligations all attach to the network side of the line. Faults on your own side fall outside all of that, and you carry both the repair cost and the inconvenience. Getting the diagnosis right at the outset decides which set of rules applies and who ultimately pays.
How damage during the all-IP switchover changes the picture
As Openreach migrates the network to all-IP under its published programme, with the legacy PSTN being withdrawn as the migration completes in 2027, the shape of a typical line fault is shifting. On a digital voice line the call no longer travels over a dedicated copper circuit to the exchange; instead it runs as data over your broadband connection and out through the back of your router. The drop wire, the cabinet and the fibre or copper feeding the property remain Openreach territory, but the point of failure for a household is increasingly the broadband service and the router rather than a snapped overhead wire.
The demarcation principle still holds, but the items on each side of it change. A dead digital voice service can stem from a broadband outage on the Openreach network, which the provider raises in the usual way, or from the customer's own router, power supply or in-home setup, which remains the householder's responsibility just as internal wiring always was. One practical consequence is that a digital line will not work in a power cut unless battery back-up keeps the router running, so a fault that looks like line damage during an outage may simply be loss of power. Testing methodically, and reporting symptoms clearly to the provider, remains the route to working out which side of the boundary a problem sits on.
Frequently Asked Questions
Who is responsible for fixing my phone line?
Openreach is responsible for the line and equipment up to and including the master socket, and repairs network faults through your provider at no charge. You are responsible for everything on the inside of the master socket, including extension wiring and handsets. The master socket is the boundary that decides which party fixes a given fault, and testing in the socket behind the faceplate is the quickest way to establish which side a problem falls on.
Who do I call if my landline line is damaged?
Call your phone or broadband provider, because residential customers cannot contact Openreach directly. The provider tests the line and books an Openreach engineer if the damage is on the network side. If the damage is to your own internal wiring or equipment, you arrange that repair yourself, either by replacing the faulty item or by hiring an independent telecoms contractor.
What is Openreach responsible for?
Openreach is responsible for the access network: the exchange equipment, street cabinets, underground and overhead cabling, the drop wire to your home and the master socket. It repairs faults on this network through the providers that resell its service. It is not responsible for your internal wiring, sockets or handsets, and it does not take fault reports or sell directly to residential customers.
Am I responsible for wiring inside my home?
Yes. Any wiring, extension sockets, filters and handsets on the customer side of the master socket belong to you and are your responsibility to maintain and repair. If a fault is traced to this internal wiring, an Openreach engineer visit can be chargeable. Testing at the master socket first helps confirm where the fault lies and avoids paying for a visit that finds the network healthy.
How do I report a damaged phone line?
Plug a working phone into the test socket behind the master socket faceplate to check whether the fault is network-side or internal. Then report it to your provider, telling them the result of that test and describing the symptoms precisely. The provider raises a network fault with Openreach if needed, and you should record the date and any reference number in case a compensation claim follows.
