Power Cut: What to Do and Who to Call

A power cut is any interruption to your electricity supply. It can last a few seconds or several days. It can affect a single property, a street, a neighbourhood, or an entire region. The cause can be external (a fault on the Distribution Network Operator's network, severe weather damage to overhead lines, planned maintenance) or internal (a tripped protective device in your own consumer unit, a failed main switch, a fault on your internal wiring).

Understanding the difference between an external power cut and an internal fault is the single most important thing you can do when the lights go out. An external power cut is the DNO's responsibility. An internal fault is your responsibility — and you need a qualified electrician to investigate and fix it.

This guide covers both scenarios. It tells you exactly what to do, step by step, when you lose power — whether the problem is on the network or inside your property.

When your power goes off unexpectedly, do not panic. Follow these steps in order:

These four steps take less than two minutes and will tell you whether the problem is external (DNO) or internal (your wiring). That distinction determines everything that follows.

Your consumer unit is the grey or white metal box — usually mounted near the front door, under the stairs, or in a cupboard — that contains the main switch, RCDs, and MCBs for your property. It is the central control point for your electrical installation.

When you open the cover (it usually clips or screws off), you will see rows of switches. Here is what to look for:

If you have reset the tripped device and the power is restored, monitor it for the next few hours. If it trips again, the underlying fault has not been resolved and you need professional investigation.

105 is the free, 24/7 power cut number for the UK. It connects you directly to your local Distribution Network Operator (DNO) — the company responsible for the electricity cables and infrastructure in your area.

You do not need to know which DNO covers your area. The 105 service uses your phone location or postcode to route the call to the correct operator. You can also check for power cuts online at your DNO's website — most have live outage maps showing current and planned interruptions.

The six main DNOs covering England, Scotland, and Wales are: UK Power Networks (South and East England), National Grid Electricity Distribution (Midlands, South West, Wales), Northern Powergrid (North East, Yorkshire), Electricity North West, SP Energy Networks (Central and Southern Scotland, Merseyside, North Wales), and Scottish and Southern Electricity Networks (North Scotland, Central Southern England).

Understanding the boundary between the DNO's responsibility and yours is critical. The boundary point is your electricity meter and the main fuse (also called the service fuse or cut-out). Everything on the network side of the meter — the incoming cable, the service fuse, the overhead or underground supply — is the DNO's responsibility. Everything on your side of the meter — the meter tails, consumer unit, wiring, sockets, switches, and appliances — is your responsibility.

If you call the DNO and they confirm the network supply is healthy, the fault is on your side. You will need a qualified electrician to investigate. The DNO will not fix internal faults — that is not their job, and they are not qualified to work on your installation.

If you are unsure whether the fault is on the DNO's side or yours, look at the main fuse (usually a black or brown unit near the meter). If the main fuse has blown, only the DNO can replace it — you must not open or tamper with the service fuse. Call 105 and report it.

Some power-related situations are emergencies. If you encounter any of the following, act immediately:

In any electrical emergency, the priority is human safety first. Turn off the power if it is safe to do so, evacuate if necessary, and call for help. Do not attempt any electrical work yourself in an emergency situation.

Not every power cut needs an electrician. But internal faults — problems with your own wiring, consumer unit, or appliances — require professional investigation. Call a qualified electrician if:

When you call an electrician for a power cut callout, make sure they are registered with a competent person scheme (NICEIC, NAPIT, or ELECSA) and hold an inspection and testing qualification. A general handyman is not qualified to diagnose electrical faults.

Power cuts are inevitable — especially during winter storms. A few simple preparations can make a big difference:

Test your RCDs at least once every three months by pressing the test button on each RCD in your consumer unit. The RCD should trip immediately when you press the button, cutting power to the circuits it protects. If it does not trip, the RCD may be faulty and should be replaced by an electrician. This simple test takes 30 seconds and could save your life.

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