A power cut is the most likely interruption a UK household will meet, and the easiest to be ready for. Four things cover almost all of it: light, warmth, a way to hear official advice, and a charged phone.
Light first
A torch where you can reach it without crossing a dark room, and a second one so nobody waits. Wind-up torches remove the battery question. Candles are a last resort, not a plan, particularly with children or pets in the house.
Head torches are worth one line of their own. Hands free light is the difference between finding the fuse box and holding a phone in your teeth.
Then warmth
Most UK heating stops when the electricity does, even with a gas boiler, because the controls and pump need power. Blankets, a warm layer each and something on the floor are enough for a few hours. Close the doors of rooms you are not using and stay in one room together.
Never bring a barbecue, camping stove or generator indoors, including into a garage or a porch. That is the one hard rule on this page.
Then information
A battery or wind-up radio tunes to local stations that carry official updates, which is how you find out how wide the cut is and how long it is expected to last. It is also worth writing down your distribution network operator’s number and keeping it with your documents, because 105 connects you to them from any phone in England, Scotland and Wales.
Then the phone
A charged power bank keeps one phone alive for a day or two. Keep it with the torch rather than in a drawer of cables, and top it up when the clocks change so it is not flat when you need it.
The fridge and freezer
Keep both closed. A full freezer holds its temperature for around twenty-four hours, a half full one for less. Ready-to-eat food on the shelf means you are not opening the fridge to decide what to do about dinner.
Know where it all is
Owning these things and finding them are different problems. Mark the torch, the radio and the power bank for Emergency view, and the black screen lists them with the cupboard each one is in, lit by the phone you are already holding.