I live in the US, and will be traveling to Scotland. I will need to charge my laptop and phone (macbook and iPhone if it matters) while I am there, and I have been receiving some mixed advice about what kind of power adapter and/or convertor I need to get. All my devices have the standard US type B power plugs, while in the UK, as I understand it, they use type G.

  • Some people have said that all I need is a cheap little adapter that converts between type B and type G plugs, like this one. They say that my devices "can handle" the difference in voltage.
  • Others say that I need a fancy converter to convert between the different voltages in the two countries.

Which is correct, and why?

  • 2
    @MarkJohnson when I moved from USA to Europe I had to buy a step up transformer for 220/240v powered devices such as TV & deathlike. However,laptops already have a transformer in the charger, so no extra hardware was necessary
    – Mawg
    Commented Sep 29, 2019 at 7:19
  • 5
    The adapter you have linked to is unfused and is illegal to use in the UK. You would be better to wait until you get to the UK and buy one here that complies with safety regulations. They're in all large supermarkets, Boots and Argos stores. Eg argos.co.uk/product/8556295
    – Owain
    Commented Sep 29, 2019 at 19:42
  • 2
    @smci it is actually true that many desktop PC's these days still have a small red switch in the back that you must manually switch to the proper voltage. I never really thought about why computers have this, but now I know! That said, you are right that I've never seen this on a laptop.
    – Bunji
    Commented Sep 29, 2019 at 20:05
  • 1
    @Bunji: no, only desktops, laptops pretty much never do. Yes, desktops may need to be manually switched, to avoid sending the power supply up in smoke. You asked about a laptop.
    – smci
    Commented Sep 29, 2019 at 20:07
  • 4
    I echo @Owain's comment. DO NOT BUY THE ADAPTOR YOU LINKED. Wait till you get to the UK then buy one from a reputable source. Electricity in homes is more dangerous in the UK than it is in the US due to higher voltage and much higher current wiring, so extra safety measures are normally present on our plugs — which won't be present on anything you can buy in the US. You'll be spending a little more most likely but it's worth it for the peace of mind that you aren't going to shock yourself or burn your hotel down...
    – Muzer
    Commented Sep 29, 2019 at 20:13

4 Answers 4


Almost certainly, each AC to DC converter you have will support both UK and US voltages, and you do not need a voltage converter.

To be absolutely sure, look at the back of your laptop's charger and your AC-to-USB plug. There should be a label that, among other things, specifies supported input voltages and AC frequencies. If it says something like "100-240V" and "50-60Hz" you only need a simple plug type converter.

  • 9
    As a Scot who lives in the US but often travels back to Scotland, I endorse this answer :) Unless you have some weird knockoff, the Apple chargers will have no problem with the voltages. My preference is plug convertor that has a couple of USB sockets built in. Commented Sep 28, 2019 at 17:14
  • 4
    The only thing I have that does not support 100-240 is my electric toothbrush. Laptop charger, phone chargers, line to USB converter, all do 100-240 Commented Sep 29, 2019 at 4:29
  • The vast majority of electronics support 100-240 (since they're transforming the voltage anyway); things that don't tend to be more mechanical appliances, like that electric toothbrush, or hairdryers, toasters etc, that apply the voltage to a motor, heater etc (though I think a growing number of these do support 100-240, maybe because they increasingly include some electronics) Commented Sep 30, 2019 at 1:11

The Apple website states:

You should use the appropriate wattage power adapter for your Mac notebook. You can use a compatible higher wattage adapter without issue, but it won't make your computer charge faster or operate differently. Lower wattage adapters don't provide enough power.

The adapters are rated at a higher voltage and should be fine.

  • 3
    I have this kit, but it won't work to charge an iPhone, unless you're charging the phone by connecting it to the MacBook (possible, but cumbersome). This travel kit does work for the iPad charger, which will also work with an iPhone (USB connector). Commented Sep 28, 2019 at 22:06
  • 2
    @Mike is correct: one can't use any of these to charge an iPhone directly. But I always travel with a MacBook Air, its power supply, and a simple plug adapter that'll work in the country I'm in. When I get where I'm going, I plug in the computer, If the phone needs juice, I can plug it into the computer or use the Apple wall wart I also carry in my goody bag. Commented Sep 28, 2019 at 23:01
  • 4
    Lifehack: The internal connector used by Apple to attach these various plugs into their power bricks is compatible with a standard IEC C7/C8 "figure-8" plug. Any power cord with (e.g.) a UK plug at one end and a C7 connector at the other (like any one of these) can be used to charge your Mac by pulling the "duckhead" off the power brick and plugging the cord in its place. It looks ugly, but works fine. Commented Sep 29, 2019 at 10:00
  • 4
    Ah overpriced crap that can be had without the brand name, what and apple thing to do.
    – Sam
    Commented Sep 29, 2019 at 15:27

1) For your MacBook adapter: you need neither. Just simply buy a UK duckhead for your MacBook, already.


  • the outrageously overpriced official "Apple World Travel Adapter set" (which is just five outrageously overpriced duckheads in a box), or
  • (unofficial third-party) individual duckheads (you can't find these on Amazon, only on eBay, for (cough, cough) legal reasons). Yes, the UK duckhead will have an earth prong but probably won't be fused. So don't leave it plugged in overnight or unattended.

Context: I just got back from Europe with my MacBook, and before I went I spent the princely total of US$5.50 on UK + EU duckheads (+ $15 for the world travel adapter). I researched this heavily before I went. Apple egregiously abuses so-called "intellectual-property" laws to legally intimidate competitors from selling duckheads in the US, i.e. a piece of plastic with a few metal bits, to preserve their obscene margins.

2) For your phone charger, no you do not need a voltage converter, you just get an adapter (world travel adapter).

A neat and compact solution is a world travel adapter with built-in (twin) USB, better still if it's twin 2.2A USB; you can even get quad-USB if you have lots of devices. These are the ones with multi-type A/B/C/G with quick-slide retractable prongs, they're lightweight, compact and retractable so they fit nicely into carry-on baggage, good for a quick use at the boarding gate, cafe etc. Ceptics is a superb brand. Just be gentle with the mechanism when you retract one type of prong and extend the other.

As to the ambiguities in the phrasing of your question: if "device" = laptop then no you don't need a voltage converter (but do obviously still need an adapter); laptops have universal voltage converters. Only if "device" = shaver/kettle/heater/desktop/other power appliance might you need an actual voltage converter. But that wasn't what the question asked about.

  • 2
    This answer brought to you by the "CE" and "CCC" certification marks... Commented Sep 29, 2019 at 20:52
  • @Harper: you seem to have first upvoted this then downvoted it. Why? If you have a valid criticism then say so. I didn't say "buy stuff that isn't CCC/CE certified". I did point out Apple enjoys an obscene margin on its own-brand stuff.
    – smci
    Commented Sep 29, 2019 at 22:51
  • @smci: If I recall correctly, I've seen Harper denounce the CE mark as a sign of particularly low quality. I think he's trying to criticize you for recommending CE-marked adapters, which he considers crap. Commented Sep 29, 2019 at 23:48
  • @HenningMakholm: I said nothing at all about certification, so if that's why he downvoted, that's unreasonable. I'm not into "device nationalism"...
    – smci
    Commented Sep 29, 2019 at 23:58
  • @Harper: your previous comments were deleted. An Apple duckhead is literally a piece of plastic, explain if you can how certification is specifically relevant to that, for anything other than preserving Apple's profit margins. I'm still not seeing any valid point from you, and we've asked you several times already.
    – smci
    Commented Oct 17, 2019 at 15:47

Look at the device. If it says 120-240V, you're all set

It may say a wider range like 100-240V (or 90-264V which is that +/-10%). 100V comes from Japan, if you're wondering.

Your Apple branded chargers will all be multi-voltage. Third party chargers may vary, but in all probability, they're multi-voltage too because of the magic of switching power supplies.

Since they are multi-voltage, all you need is an adapter to physically connect the US prongs to the UK socket. This device will contain only copper and plastic. Beware cheap Cheese junk; look for the mark of competent testing labs such as UL, CSA, BSI, TUV, ETL, etc.

Most things care about voltage. Some things also care about frequency. So check each device individualy.

Any run-of-the-mill IEC C7 cord will also do

You've seen C7. It's is the little socket used on everyone else's laptop power supplies, tape recorders, projectors etc.

On some Apple adapters, you can remove the plug portion. That exploses an inlet* for IEC C7. You've seen C7 before. You can use any run-of-the-mill IEC C7 cord, or you can get different Apple plug modules for different countries that snap in just like the original, if you don't want to drag a cord around.

The standard, bulky UK socket is called a BS1363

It's much more productive to search for "BS1363" than "G". So for instance you might search for a C7 to BS1363 cord.

Note a couple unique things about BS1363 that differ from the compact US sockets:

  • The BS1363 socket has a switch on it. If the socket is dead, try the switch.
  • The BS1363 plug has a fuse in it. Yeah. Seriously. So if nothing else is working, check the fuse.

* Technically speaking, an "inlet for IEC C7" is C8, but let's not confuse the matter. C7 is what you need.

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