Permanently using an extension lead is strongly discouraged — it's a fire risk. The proper solution is to have additional sockets installed.
🏠Homeowner view
Extension leads are designed for temporary use, not as a permanent part of your home's wiring. Using one long-term creates several risks. Extension leads can overheat if coiled up — always unroll them fully if they're carrying any significant load. They can be damaged by furniture legs standing on them or by being run under carpets (where heat builds up unseen). Their plugs and sockets become loose over time, creating arcing. And most extension leads are not rated for the combined load of everything plugged into them. If you regularly rely on extension leads, the right fix is to have an electrician add properly installed wall sockets. This is safer and actually cheaper in the long run. If you must use one temporarily, buy a quality UK-standard lead with surge protection, never daisy-chain two extension leads together, and replace any that show signs of damage.