Plug types: which adapter you need
The world uses more than a dozen plug and socket designs, identified by letters. You do not need to memorise them, but knowing the main ones helps you pack the right adapter.
These are the types you will meet most often:
- Type A and B: flat parallel pins, with B adding a round earth pin. Used in the United States, Canada, Mexico, Japan and parts of Central and South America and the Caribbean.
- Type C: two round pins, the classic European plug for small devices. It fits most sockets across continental Europe and many other countries.
- Type E and F: two round pins with an earth connection, used in France, Germany and much of continental Europe. Type C plugs fit these sockets too.
- Type G: three rectangular pins. Used in the UK, Ireland, Malta, Cyprus, Hong Kong, Singapore, Malaysia and several other countries.
- Type I: two angled flat pins, often with a third. Used in Australia, New Zealand and China, among others; China also uses Type A.
- Type J and L: three round pins in a line or a shallow triangle. Used in Switzerland and Italy respectively; both accept Type C plugs.
- Type D and M: three large round pins. Used in India, South Africa and some neighbouring countries.
Adapters, voltage and chargers
A plug adapter only changes the shape of the plug. It does not change the voltage. Mains electricity is roughly 100 to 127 volts in North America, Japan and some other countries, and 220 to 240 volts in most of the rest of the world.
The good news is that nearly all phone, tablet, laptop and camera chargers are designed to work anywhere from 100 to 240 volts. Look for the small print on the charger, which usually reads something like input 100 to 240 volts, 50/60 hertz. If you see that, a simple adapter is all you need. Devices that heat up, such as hair dryers, straighteners and travel kettles, are a different matter. Many are single-voltage and can be damaged, or simply not work properly, on the wrong supply, so either buy a dual-voltage model or leave them at home.
A universal travel adapter that covers several plug types is the simplest option if you travel to many countries. Choose one with built-in USB-C ports and you may not need a separate charger at all.
To cut down on bulk, consider a single multi-port USB-C charger. Modern chargers using gallium nitride, often sold as GaN chargers, are much smaller than older designs and can charge a laptop, phone and earbuds from one plug. Pair it with two or three good USB-C cables, plus any older cables your devices still need, such as Lightning for older iPhones. A short cable is handy on planes and trains; a longer one helps in hotel rooms where sockets are far from the bed.
Power banks on planes
Power banks contain lithium batteries, and airlines treat them carefully because of the fire risk. The rules are broadly consistent around the world, but individual airlines can be stricter, so always check your airline's own policy before you fly.
The core points are:
- Power banks and spare lithium batteries must go in your cabin baggage, never in checked luggage. If your cabin bag is checked at the gate, take the power bank out first.
- Capacity is measured in watt-hours. Under common international guidance, batteries up to 100 watt-hours are allowed without special permission, those between 100 and 160 watt-hours need airline approval, and larger ones are generally not allowed on passenger planes.
- To work out watt-hours, multiply the capacity in milliamp-hours by the battery's voltage, usually 3.6 or 3.7 volts, and divide by 1,000. A 20,000 milliamp-hour power bank at 3.7 volts is 74 watt-hours, comfortably under the common limit.
- A growing number of airlines restrict using or charging power banks during the flight, or require them to be kept in sight rather than in the overhead locker. Follow the crew's instructions.
- Buy power banks from reputable brands, with the capacity clearly printed on the case. Unmarked or damaged power banks may be refused at security.
Apps to set up before you leave
Most travel apps work best if you install and sign in to them at home, on reliable Wi-Fi, where you can deal with verification codes and passwords calmly.
Offline maps are the single most useful thing to prepare. Google Maps lets you download areas for offline use, Apple Maps supports offline maps on recent versions of iOS, and dedicated apps built on open map data work entirely offline. Download your destination cities and any rural areas you plan to drive through, where coverage may be patchy. Offline maps still show your position using GPS, which does not need mobile data.
Translation apps can also work offline if you download the language packs in advance, and many can translate text through the camera, which is ideal for menus and signs. Other apps worth setting up include your airline's app for boarding passes and delay alerts, a ride-hailing app that operates in your destination, your bank's app with notifications turned on, and the local public transport app or route planner if there is one.
Finally, save copies of important documents somewhere secure that you can reach offline, such as your passport details, travel insurance policy and booking confirmations, and make sure two-factor authentication codes for your email and bank will still reach you while you are away.
Staying online: eSIM, pocket Wi-Fi or local SIM
There are three main ways to get mobile data abroad other than roaming on your home plan, and each suits different travellers.
A travel eSIM is a digital SIM that you install on your phone by scanning a QR code or through an app, often before you leave home. It gives you mobile data abroad without swapping a physical card, and you can usually keep your home SIM active alongside it for calls and texts. It needs a phone that supports eSIM and is not locked to a single network. Your phone can share its connection with a laptop or a travel companion using its hotspot feature, though this uses more battery.
A pocket Wi-Fi router is a small portable device that connects to a local mobile network and creates a Wi-Fi hotspot that several devices can join. It works with any Wi-Fi device, including phones that do not support eSIM, and can be convenient for a family or group. On the other hand, it is one more device to charge and carry, everyone needs to stay within range, and rented units usually need to be collected and returned.
A local physical SIM card, bought on arrival, is another option in many countries. It can offer a local phone number, which is useful for some services, but you need to find a shop, may need to show identification, and have to keep your home SIM safe while you are away.
There is no single best choice. Solo travellers and couples with modern phones often find an eSIM simplest; groups with mixed devices sometimes prefer a pocket Wi-Fi unit. Our guide to what an eSIM is explains the technology in more detail, and our guide to eSIM-compatible phones helps you check your device.
The checklist
Here is a compact list to work from. Not everyone needs everything, but most travellers will want the first six items.
- A universal or destination-specific plug adapter, ideally with USB-C ports.
- A compact multi-port USB-C charger.
- Two or three charging cables for your devices.
- A power bank of 20,000 milliamp-hours or less, packed in your cabin bag.
- Offline maps and translation packs downloaded for your destination.
- A plan for mobile data, whether a travel eSIM, pocket Wi-Fi or local SIM.
- Wired or wireless earbuds, plus a two-prong or headphone adapter if you want to use older in-flight entertainment systems.
- A luggage tracker in your checked bag, if you like the reassurance.
- A small extension lead or multi-socket adapter for hotel rooms with few sockets, where allowed.
- An e-reader or downloaded films and podcasts for long journeys.