If you’re soon arriving or have just arrived and are wondering where to buy a SIM card in London, there are three basic options: at the airport, from a local shop or order online. The best-value option is usually to avoid the big providers and order one of the alternative provider prepaid SIMs online.

tldr; our favourites:
SMARTY and VOXI with pricing from £10.00 and generous data allowances are London Cheapo’s top rated prepaid UK SIMs, plus they often have special offers with extra data, check them out or read on for full details.

Buying a SIM card at Heathrow Airport

At Heathrow, there are SIM-card vending machines in the baggage reclaim hall, as well as SIM cards for sale at the shops in the arrivals hall. This is probably the most straightforward way of picking up a SIM card on arrival in the UK. However, you may be limited in choice and you won’t be getting the best value. But if you’re reading this on your phone at the airport and don’t want to quibble over a few quid, then you might be happy with this as a quick solution.

The main things to bear in mind are: network provider coverage and the duration of your stay in the UK. If you’re staying in London only, then network coverage should be good on all providers, but if you’re visiting more remote ares, see the section below on network coverage. In short, you’ll probably get the most reliable coverage with a provider on the EE or Vodafone networks, like VOXI. In terms of duration, if you’re staying more than a month, then the airport options may not be ideal, and you will be better off ordering one of the prepaid SIMs with a rolling monthly plan.

SIM cards at WH SMITH Heathrow terminal 5
UK SIM cards at WHSmith, Heathrow Terminal 5. | Photo by Chris Kirkland

Shops selling SIM cards in London

If you’re in central London, you won’t have to walk far to find a shop selling SIM cards.

The big mobile network providers—Three, O2, Vodafone and EE—all have multiple shops around London. For example, you’ll find the lot of them on Oxford Street. You’ll be able to buy a short-term prepaid or PAYG SIM in store, and have one of the staff help you install the SIM correctly.

Apart from the big network providers’ own stores, other shops you can walk into and buy a SIM card in London include:

  • Carphone Warehouse
  • WHSmith newsagents
  • Boots drugstores
  • Superdrug drugstores
  • Various small independent newsagents/convenience stores

Carphone Warehouse is a mobile phone specialist that stocks multiple networks’ SIM cards, so you can compare options in store. Plus, staff will be on hand to help you choose. Superdrug offers it’s own branded SIM card (on the Three network), whilst WHSmith and Boots often stock SIM cards from some of the major providers as well as MVNO SIM cards (Lyca, etc.). Finally you’ll find some independent newsagents stocking SIM cards—if you’re away from central London, you might find this is the nearest option.

Superdrug shop with SIM card sign outside
A SIM card and doggy can be a good combo. | Photo by Chris Kirkland

The best UK SIM card deals are online

You’ll very likely get the best value if you order a SIM card online, which is quick and easy to do. SMARTY and VOXI are strong contenders for the best pre-paid UK SIM cards, and often have special offers with extra data. See our article on UK SIM cards for a fuller comparison.

Whilst you’ll have to wait a day or so for delivery, it will save you the time of walking around shops and schlepping across London for an afternoon. Also, if you’re yet to arrive in the UK, you can order in advance and have it delivered to your hotel, Airbnb or wherever it is you’re staying, before you arrive.

Network coverage and data speed

If you’re based in London, then it doesn’t really matter which network provider (the actual underlying telecoms network, sometimes different from the brand of the SIM card) you are using as they all have good 4G and sometimes 5G coverage in the UK’s major cities. If you’re going to stray off the beaten track and be spending time somewhere more rural, then you might want to check which network you’re about to sign up for, as coverage can get a little patchy in the countryside.

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In terms of coverage, overall EE is probably the best network, followed by O2 and Vodafone, with Three coming in last. All the providers have a network coverage map (e.g. Three, Vodafone, O2, and EE), so if you want to be sure you’ll be covered, you can check the area you’ll be in.

With the MVNO providers, you’ll have to check which network they use, but for the main ones we recommend: VOXI is a subsidiary of Vodafone, Lyca Mobile and Plusnet operate on the EE network, SMARTY and iD Mobile run on Three, and GiffGaff uses the O2 network.

More on SIM cards

If you’re a world-cheapo, check out the articles about SIM cards and eSIMs for travel on our sister sites (Hong Kong Cheapo, and Tokyo Cheapo):

While we do our best to ensure it’s correct, information is subject to change.

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