The core categories
Water
Plan for three days. Government guidance uses 3 litres per person per day for drinking, with more needed for cooking and washing.
Food
Keep non-perishable food that does not depend on refrigeration or cooking. Choose food you would normally eat.
Light + warmth
A torch and spare batteries, plus blankets, sleeping bags or warm clothing. Government guidance notes torches are safer than candles.
Communication
A charged power bank, written contact numbers and a battery or wind-up radio can reduce dependence on phone networks and mains power.
Medicines + household needs
Plan for prescriptions, medical devices, baby supplies, pet needs and any other household-specific dependencies.
Money + documents
Keep essential information accessible offline. Government guidance also suggests considering some cash in case electronic payments are disrupted.