US plugs do not fit London sockets. Which Type G adapter to buy, how to tell a dual-voltage charger from a 120-volt dryer, and what to do about bathrooms, Paris, and power banks.
As an Amazon Associate we earn from qualifying purchases.
The short answer
London does not use the plug in your suitcase. The UK standard is a Type G socket at 230 volts and 50 hertz. The United States uses Type A and Type B plugs at 120 volts and 60 hertz. A US plug will not go into a British socket, so you need a physical adapter. You need a voltage converter only when the device itself cannot take 230 volts.
Read the label on the power brick, the line that starts with "Input." If it says 100–240V and 50/60Hz, the charger already accepts British power and the adapter is the only extra thing you buy. Phone and laptop chargers are usually built that way. Hair dryers and flat irons bought for American bathrooms usually are not. Those plug, voltage, and frequency figures are from the IEC World Plugs list, checked October 23, 2026. Ireland is Type G at the same 230 volts, so the adapter you buy for London works there too.
An adapter is not a converter
An adapter changes the shape of the plug. It does not change the voltage, and it does not change the frequency. The UK supply is nearly twice a US outlet, 230 volts against 120. A 120-volt-only appliance on that supply, with nothing but an adapter, is how dryers and irons fail on the first morning.
A converter steps the voltage down. For a charger that already says 100–240V, it is weight you do not need. For a high-wattage hair tool, a converter big enough to feed it is bulky and a worse buy than a dryer whose label accepts 230 volts.
Britain is 50 hertz and the US is 60. Chargers marked 50/60Hz do not care. A clock that keeps time from the wall frequency, or a motor rated only for 60Hz, can run at the wrong speed. Leave those at home.
How to read your charger's label
Turn the brick over. You want the input line, not the output line. Output is what the charger sends onward (5V, 9V, 20V, and so on). Input is what the wall must provide.
A dual-voltage input looks like "100–240V ~ 50/60Hz". A single-voltage US input looks like "120V ~ 60Hz" and nothing else. A slash, such as "120/240V", can mean a physical switch on the device. If you see a switch, set it before you plug in. If the range does not include 230, do not plug it in.
| Device | Usually dual-voltage? | What you need |
|---|---|---|
| Phone or tablet charger | Usually, if the brick says 100–240V | A Type G adapter |
| Laptop charger | Usually the same | A Type G adapter that accepts the ground pin if the brick has one |
| Compact USB-C charger | Usually; read its input line | A Type G adapter, unless that charger already has a UK plug |
| Camera or toothbrush charger | Often, not always | An adapter only after the label says so |
| Hair dryer or flat iron | Often no | A dual-voltage travel tool, not a converter |
| CPAP power supply | Often yes on recent machines; confirm that unit | A grounded Type G adapter if the label includes 230V |
"Usually" is not a promise. The label on the thing in your hand wins. If you cannot find an input line, check the manual for that model number. Do not guess.
Which adapter to buy
For a week in London, a plain Type G adapter is the one that matters. Add USB ports, a universal body, or a new charger only when you can name the reason. Type G is three rectangular blades in a triangle, and the British plug is fused, per the IEC description. Buy an adapter that accepts a grounded US plug and puts three rectangular blades in the wall. One that leaves the ground pin hanging off is a poor fit for a laptop brick.
| Category | Use it for | The trade-off |
|---|---|---|
| Plain Type G adapter, single or a 2- or 3-pack | Phones, laptops, two people sharing a room | Small and grounded. No USB ports of its own |
| Type G adapter with USB-C and USB-A | A nightstand charge without the laptop brick | Read the wattage on it. Many of those USB ports are for phones, not laptops |
| Universal travel adapter | London plus Paris or the rest of Europe | Bulkier. A listing that only says "Europe" may be Type C, which will not fit Britain |
| Compact USB-C GaN charger, about 65 watts | One brick for a phone and a USB-C laptop | A US plug on that charger still needs a Type G adapter |
Plain Type G. One grounded adapter runs a phone brick and a laptop brick. Pack a spare in the day bag. See grounded Type G adapters on Amazon. See Type G 3-packs on Amazon.
USB ports on the adapter. Useful on a nightstand. The wall blades still have to be Type G, and the wattage printed on the adapter tells you whether the USB-C port can feed a laptop or only a phone. See USB-C Type G adapters on Amazon.
Universal. Buy this only if the same ticket includes Paris or another country on the continent. Confirm Type G, or UK, on the listing. See universal travel adapters on Amazon.
A 65-watt USB-C charger. This is the compact multi-port brick for a phone and a laptop that charges over USB-C. Check its input line for 100–240V. If the plug is American, you still need the Type G adapter, unless a UK plug is actually in the box. See 65W travel GaN chargers on Amazon.
Cable and power bank. Sockets sit beside the bed, not on the desk. See USB-C cables on Amazon. Spare lithium-ion batteries, including power banks, go in the cabin. The FAA says to take them out if a bag is checked at the gate. Up to 100 watt-hours is allowed for personal use. The 101–160 watt-hour range needs airline approval, and you may bring two of those larger spares. Over 160 watt-hours is not allowed, and airlines may set stricter limits, so check yours. Newer batteries print the watt-hour figure; otherwise multiply volts by amp-hours. See USB-C power banks on Amazon.
Skip a US power strip. An adapter does not make it safe on a British socket, and it does not belong in a bathroom.
Hotel rooms and bathroom sockets
UK hotel rooms are wired for Type G. Where you stay changes how far that socket is from the bed, which is a reason to read where to stay in London before you book. The plug is the same in Westminster and in Kensington.
The bathroom is the exception. Electrical Safety First says ordinary sockets are not allowed within 2.5 meters of a bath or shower tray, apart from shaver-supply units. Those points are allowed closer in only when they are extra-low voltage or they meet BS EN IEC 61558-2-5. They are for shavers, not hair dryers. Do not run an extension lead into the bathroom. Dry your hair in the bedroom, from a normal socket, with a dryer whose label accepts 230 volts.
Do not count on a USB port in a lamp. Some rooms have one. Many do not, and a lamp port will not charge a laptop.
Going on to Paris
A Type G adapter is useless on the other side of the Eurostar. France uses Type C and Type E sockets, still at 230 volts and 50 hertz, on the same IEC list. Type C is the two round pins of a Europlug. Type E adds a ground through a pin in the socket. Your UK adapter fits neither.
If Paris is on this itinerary, pack a second adapter or a universal one that includes Type G and Type C/E. Our Paris day trip from London guide covers the train day itself. The voltage does not get easier there. A device that was fine in London on a dual-voltage label will be fine. A 120-volt dryer is still the wrong dryer in France.
Hair tools, CPAPs, and other tricky devices
If the dryer or flat iron does not say 100–240V, 220–240V, or "dual voltage" on its own label, leave it at home. The word "travel" on the box is not a voltage range. See dual-voltage travel hair dryers on Amazon. See dual-voltage flat irons on Amazon. Skip the converter: a dual-voltage tool does that job without a second brick.
CPAPs and other plugged-in medical devices need the same check, on the power supply that shipped with that machine. If the input includes 230V, a grounded Type G adapter is the usual fix. If it does not, ask the manufacturer before you travel, and tell the hotel so they can point you to a socket you can reach from the bed. This is packing advice, not medical advice. Toothbrush and camera chargers are usually fine and occasionally not. Read those labels too.
What else to pack
The adapter is the electrical item London actually requires. If you are here for the lights and the markets, Christmas in London is how those weeks run, and you will come back after dark with a phone that needs a charge. A Studio Tour day is the same problem. Harry Potter Studio Tour tips cover the tickets and the timing.
Still weighing the trip? Is London worth visiting is the honest version. The neighborhood decides the commute. The plug does not change from one to the next.
