If you’re soon arriving or have just arrived and wondering where to buy a SIM card in London, there are three basic options: at the airport, from a local shop or order online. Typically, the best value option is to avoid the big providers and order online from an MVNO provider offering prepaid SIMs
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 straight forward way of picking up a SIM card on arrival in the UK. However, you may be somewhat limited in choice and unlikely to get 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 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 monthly plan.
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 them all 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 include Carphone Warehouse, WHSmith newsagents, Boots drugstore, Superdrug drugstore and 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.
Best UK SIM card deals are online
Last but not least, you’ll very likely get the best value if you order a SIM card online. 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 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 where 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 speding 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. Overall EE is 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.