How to Prepare for a Power Cut in the UK

Power cuts are familiar in British weather — a storm brings a tree down, a fault takes out a street, the lights flicker and then return. Official Prepare guidance says the UK has a resilient electricity system and that most cuts are short and local. It also says more widespread and longer outages can happen, potentially lasting several days.

Without power, gas ovens, boilers, heat pumps and home internet will not work. Mobile signal can fail if a local mast is affected. Mains water can also be disrupted during and after some cuts. This guide summarises published advice so you can plan calmly. It is not a promise about how long any particular cut will last.

Before a cut: a short, useful list

Prepare recommends:

A battery or wind-up torch and spare batteries. Torches are safer than candles. Using your phone as a torch drains a battery you may need for calls.
At least three days of bottled water at 3 litres per person per day, and food that does not need cooking, plus a tin opener. Include ready-to-feed baby formula and pet food if you need them.
Signing up to the Priority Services Register if you are eligible, so your energy supplier knows you may need extra support. Official pages note that lots of households are eligible, including those with children under 5. In Northern Ireland these are called Customer Care Registers.
Finding your load block letter at powercut105.com, or on some electricity bills. In the unlikely event of a national energy shortage, emergency cuts could be scheduled by area for around three hours at a time.
A small amount of cash, if electronic payments or cash machines are disrupted.
The number to report a cut, written on paper: 105 in England, Scotland and Wales (free), and 03457 643643 in Northern Ireland.

If the internet and mobile signal go as well:

Keep a battery or wind-up radio, and write down station frequencies. A car radio can be used, although in severe weather it may be safer to stay inside.
If your only way of making emergency calls is a landline, or you have a telecare kit on that line, ask the provider whether it will work in a power cut. Official guidance says providers may offer a backup battery solution for a minimum of one hour so you can still call the emergency services.
If you use a personal alarm or connected health equipment, such as some diabetes sensors, ask the manufacturer how it behaves without mains power.

If you use medical equipment that needs electricity, Prepare says you should make a plan now with your care provider or clinical team, including who to contact.

During a cut

Report it on your network operator’s website if you can, or call 105 (or the Northern Ireland number).
Keep away from damaged power lines. Official guidance warns that electricity at high voltages can jump gaps with no warning.
Turn off irons, ovens, electric fires and fryers. Unplug televisions and computers, which can be damaged by a surge when power returns.
Keep warm with blankets and layered clothing. Close unused rooms and curtains to keep heat in. Older adults, babies, young children and people with long-term health problems are most likely to become ill if they get too cold. See How to stay warm during a winter power cut.
Check on neighbours if you are able, and share spare blankets or food if you can do so safely.
For news, use a battery or wind-up radio. Try FM and digital modes.
If you have a life-threatening emergency and no working landline backup, attempt 999 or 112 from a mobile. Official guidance notes that emergency calls automatically roam onto available networks, and you might pick up signal from a nearby area that still has power.

Food in the fridge and freezer

The Food Standards Agency advises that a power cut of less than four hours is unlikely to affect the safety of chilled or frozen food. If it lasts longer:

Keep fridge and freezer doors closed. A fridge should stay cold for up to four hours. Food in a full freezer should stay frozen for up to 48 hours, or 24 hours if the freezer is half full. The FSA describes these as estimates.
In a power cut, chilled food can be kept in a fridge below 8°C. If the temperature reaches 8°C or above, eat food that normally needs refrigeration within four hours first.
If the weather outside is below 8°C, food can be stored outside in a clean, sealed container, out of sunlight and away from animals.
Eat chilled foods first, then thawed frozen food that does not need cooking, then ordinary cupboard food.

Follow the FSA page rather than guessing. If you are unsure whether food is safe, throw it away — especially for anyone at higher risk.

The FSA page applies in England, Northern Ireland and Wales. If you live in Scotland, check Food Standards Scotland for consumer food-safety advice rather than assuming the same wording applies.

Baby formula if you cannot boil water as usual

Prepare notes that powdered formula should only be prepared with freshly boiled water and that bottled water is not usually recommended for making up feeds, because it is not sterile and may contain too much salt or sulphate. In rare circumstances, still bottled water can be used if it has no more than 200 mg/l of sodium and 250 mg/l of sulphate, boiled and cooled for no more than 30 minutes. Ready-to-feed formula is the safer official option when you cannot boil water. Check the latest NHS advice on making up infant formula.

After the power returns

Reset appliances carefully, and only restock a freezer once you have followed food-safety advice. Recharge power banks, replace any batteries you used, and jot down what you wished you had had nearby — a second torch upstairs, a written copy of a medicine list, the radio frequencies you actually use.

For the three-day household list that sits behind much of this advice, see What should be in a UK 72-hour emergency kit?.

Sources

Prepare: power cuts
Be Ready for emergencies
Food safety in a power cut, Food Standards Agency
Priority Services Register and Ofgem’s explanation

Open the 72-hour kit builder · Free checklists and official links