SIM cards and eSIM in United Kingdom

Mobile internet eSIM Best option when traveling

Guac

Recommended

Reliable mobile internet at better prices than most travel eSIMs, with polished iOS and Android apps and support for making and receiving phone calls.

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Airalo

One of the biggest travel eSIM brands, with a very large destination catalog.

Holafly

Known for unlimited-data plans in many destinations, at a higher price per gigabyte.

Buying a local SIM card No ID registration needed

Registration

Unusually for Europe, UK prepaid SIMs need no ID: you can buy and activate immediately without showing a passport. Two caveats: airport kiosk staff may ask for a passport if you top up above GBP 30, and MVNOs bought online (Giffgaff, Smarty) need registering with a UK address, where a hotel name and postcode is generally accepted.

Tourist plans and prices

Expect GBP 10 to 20 (roughly $13 to 26) for a 30-day bundle of 15 to 100 GB. Standouts in 2026: Three's 30-day pack at around GBP 15 for 100 GB with unlimited UK calls, texts and 30 days of EU roaming; Giffgaff's GBP 12 goodybag with 30 GB; and Smarty at GBP 10 for 30 GB. The SIM itself is usually free or about GBP 1.

Where to buy

Very easy. All four networks plus MVNOs are sold at Heathrow through WHSmith, Boots and Sim Local kiosks and vending machines (T2 to T5, roughly 06:00 to 23:00), and everywhere else through high-street carrier shops and supermarkets like Tesco, Sainsbury's and Asda. Giffgaff ships a SIM free worldwide if you order a few days ahead. Skip WHSmith's own-branded SIMs: they're rebadged Lyca or Lebara at a 20 to 30 percent markup with identical coverage.

Airport prices

Mild. Airport SIMs start around GBP 15 for 20 GB versus GBP 10 to 15 for bigger bundles in town or online, so the gap is small and the UK is one of the easier places to just buy on arrival.

Local eSIM

eSIM is widely supported by all four networks and the MVNOs, with no registration requirement, making the UK one of the simplest eSIM markets in Europe. A UK eSIM carries the same EU roaming limits as a physical SIM on the same network.

Local carriers

• EE

  The largest operator, with the fastest 5G rollout and the best rural coverage. Also the strongest signal in the London Underground tunnels.

• Three

  The data-heavy budget network, and the only major carrier still including free EU roaming on prepaid.

• Vodafone UK

  Strong city coverage and regarded as the best bet on intercity rail routes.

• O2

  Balanced coverage, plus free Wi-Fi hotspots on the Underground and high streets.