Two separate things catch travellers out with electrics abroad, and they're often confused for each other: the shape of the plug socket, which varies by country and simply needs a physical adapter, and the voltage of the electricity supply, which varies too and occasionally needs an actual converter rather than just an adapter. Get the shape wrong and your plug won't fit; get the voltage wrong and, in rare cases, you can damage the device.
Plug shapes: the main types you'll meet
The world uses around a dozen common plug and socket standards, usually labelled with letters. You don't need to memorise all of them — just know which one your destination uses and which one you're travelling from.
- Type A/B — flat parallel pins (A, two-pin) or with a round earth pin (B, three-pin). Used across North America, parts of Central America and Japan (Japan uses A but at a different voltage, covered below).
- Type C — the simple two round pins found across most of continental Europe, and widely compatible as the "base" plug that fits into many other European sockets even without a full adapter, though not all.
- Type D — three thick round pins in a triangle, mainly India, Nepal and Sri Lanka.
- Type E/F — the two-round-pin plugs with an earth clip or hole, used across most of continental Europe (France favours type E, Germany and much of the rest of Europe use F, and the two are cross-compatible in most sockets).
- Type G — the large rectangular three-pin plug used in the UK, Ireland, Malta, Cyprus, Hong Kong, Singapore, Malaysia and several Gulf states — a legacy of British colonial-era electrical standards.
- Type I — flat pins in a V-shape, used in Australia, New Zealand, and (in a variant) mainland China and Argentina.
- Type M and Type N — large three-round-pin variants found in southern Africa and Brazil respectively, each distinct enough to need its own adapter even though they look superficially similar to other types.
A "universal" travel adapter that covers most of these shapes is the simplest solution for anyone visiting several regions on one trip, and is genuinely worth buying rather than assembling a drawer of country-specific adapters over the years. It's a small, easy addition to a carry-on-only packing list, since it's light and rarely worth checking a bag for.
Voltage: 110–127V vs 220–240V
Alongside plug shape, countries run their mains electricity at one of two broad voltage bands: roughly 110–127V (North America, much of Central America, Japan, and a handful of others) or roughly 220–240V (most of Europe, Asia, Africa, Australia and South America). A plug adapter changes the shape of the pins so they fit the socket — it does not change the voltage passing through them.
Why most modern electronics don't need a converter
The good news: laptops, phone chargers, camera battery chargers and most modern gadgets are built with a dual-voltage (or "auto-switching") power supply, designed to accept anything from around 100V to 240V without any converter needed — only a shape adapter for the socket. Check the small print on the charger's brick or plug itself: it will state a voltage range such as "INPUT: 100–240V" if it's dual-voltage, which the overwhelming majority of modern electronics are. If it lists a single voltage figure instead, treat it as single-voltage and follow the guidance below. If you're carrying spare device batteries or a power bank as well, our guide to hand luggage rules covers where those need to travel and how they're screened at security.
When you actually need a voltage converter
A genuine step-up or step-down voltage converter is only necessary for single-voltage appliances travelling between the two voltage bands — most commonly hairdryers, straighteners, travel kettles and irons that aren't dual-voltage. Converters for anything with a heating element need to be rated for a meaningfully higher wattage than the appliance draws, since heating appliances pull far more current than electronics, and an underrated converter can overheat. For most travellers, it's simpler and safer to buy a cheap dual-voltage travel hairdryer or straightener once, rather than carrying a converter for a single-voltage one on every trip.
Japan and a few other exceptions
Japan is a useful example of how plug shape and voltage don't always follow the pattern you'd expect: it uses the same flat two-pin Type A plug as North America, but runs at 100V — close enough to North American voltage that most dual-voltage devices work without issue, though eastern and western Japan actually run at slightly different frequencies (50Hz vs 60Hz) due to a historical quirk in how the national grid was built, which occasionally affects older equipment with motors, though it's a non-issue for virtually all modern travel electronics.
A simple pre-trip check
- Look up your destination's plug type(s) — some countries genuinely use more than one, particularly former colonies or countries near a border.
- Check whether your device is dual-voltage by reading the input voltage printed on its charger or appliance body.
- Buy one decent universal adapter rather than several single-country ones if you travel to varied regions.
- For single-voltage heated appliances (hairdryers, straighteners, kettles), either buy a dual-voltage travel version or a properly rated voltage converter — don't rely on a shape adapter alone.
Keeping devices charged matters more on longer journeys — see our guide to surviving a long-haul flight for what's actually worth carrying on board, and our eSIMs for travellers guide if staying connected on arrival matters as much as staying charged. If unfamiliar electrical or travel terminology comes up while you plan, our travel glossary covers it in plain English.
Frequently asked questions
What's the difference between a plug adapter and a voltage converter?
An adapter changes the physical shape of the pins so a plug fits a different socket; it does not change the voltage. A converter actually steps the voltage up or down and is only needed for single-voltage appliances travelling between different voltage regions.
Do I need a voltage converter for my phone charger or laptop?
Almost never — check the charger for a printed input range such as "100–240V"; the vast majority of modern electronics are dual-voltage and only need a shape adapter, not a converter.
Which countries use the same plug type as the UK?
Type G, the large rectangular three-pin plug, is used in the UK, Ireland, Malta, Cyprus, Hong Kong, Singapore, Malaysia and several Gulf states, largely reflecting historical British electrical standards.
Can I buy a universal adapter that works everywhere?
Most "universal" travel adapters cover the common plug shapes for the large majority of countries, though it's worth checking the specific regions you're visiting are included, since a few plug types (particularly types M and N) aren't always covered by cheaper universal models.
Sources and further reading:
- Plug type and voltage standards by country: International Electrotechnical Commission (IEC) reference data.
- Device-specific voltage ranges: check the input rating printed on your charger or appliance.