Unplugging your phone charger the moment the battery hits 100% is one of the most repeated energy-saving habits in Britain. We have all heard it: a charger left in the socket with nothing attached keeps quietly drawing power and pushing up your bill, night after night. It sounds sensible, and for one generation of devices it was genuinely true. In 2026, though, the picture looks very different, and the humble phone charger deserves a fairer hearing.
A modern charger is barely allowed to waste anything
Since 1 April 2020, the ecodesign rules under Regulation (EU) 2019/1782 have capped how much an external power supply may draw with no device connected. A recent charger sitting in the socket with no phone attached cannot exceed 0.1 watts. Over a full year that works out at roughly 0.9 kWh, or about 23p at the July 2026 price cap rate of 26.11p per kWh.
The maths barely moves even if you exaggerate. Leaving five modern chargers plugged in permanently adds up to about 4.4 kWh, a little over a pound a year. Switching them off at the wall is not wrong, but the saving hardly registers on your bill.
To see what any always-on device really costs, you only need its idle wattage and the price of your kWh:
Why the myth refuses to die
The belief made perfect sense once. The heavy black transformers that shipped with laptops fifteen years ago could pull 4 watts or more even with nothing plugged into them. One of those ageing power bricks left permanently in the socket can burn through almost 39 kWh a year, roughly £10. That is where the fear came from, and it was handed down as gospel.
The trouble is that the design rules wiped out that waste on new products, while the habit of dashing to unplug the little phone charger survived the problem that created it. Today the gesture is close to symbolic.
Telling the two real culprits apart is still worth it. Here is what you can safely leave alone, and what is worth switching off:
- Leave a modern phone charger where it is: light, cool to the touch and ecodesign-compliant, it sips a fraction of a watt.
- Leave small, recent USB adapters plugged in: earbuds, e-readers and digital clocks cost pennies a year.
- Unplug bulky old transformers: if they stay warm when nothing is charging, they are still drawing power idle.
- Do not leave ageing laptop bricks live: those heavy black blocks are the ones that actually add up.
Where switching off genuinely pays
Standby waste is real, but it hides elsewhere. A broadband router runs 24 hours a day and can get through 150 to 300 kWh a year, about the same as a small fridge. Set-top boxes, televisions, games consoles and those old power bricks are the real culprits, and a single set-top box left on standby can cost around £17 a year on its own.
The Energy Saving Trust reckons the average home wastes around £65 a year on gadgets left on standby, while British Gas puts the potential saving as high as £147 a year for a device-heavy household. Even wireless charging pads draw about 0.25 watts continuously, more than a cable charger sitting empty.
Good to know: a wireless charging pad keeps drawing around 0.25 watts even with no phone resting on it, more than a cable charger sitting empty. If you really want to trim phantom draw, that pad is a smarter target than the charger you keep pulling out.
The smart move, then, is not to chase the phone charger but to put the TV, set-top box and console on a switched extension lead and kill the lot with one press. For a room-by-room plan it is worth browsing our consumption guides and the tips to save electricity. That is where the real tens of pounds live, while the empty charger can stay exactly where it is.
- The takeaway
- An empty phone charger costs pennies a year: you can leave it plugged in without guilt.
- Old, heavy power bricks are still worth unplugging: they run warm and waste tens of kWh.
- The real standby cost is the router, set-top box, TV and console: a switched extension lead kills them all at once.