The short verdict
For most visitors to the UK: Flysimio gives you 5 GB on EE — the UK's largest and fastest network — for around $7.50. That is the best combination of network quality and price we found. Airalo is slightly more expensive on the same network. Holafly's unlimited plan at $13.90 for 7 days makes sense only if you plan to stream or hotspot heavily. Giffgaff routes through O2, which has strong London and city coverage but falls behind EE in rural Scotland and Wales.
UK eSIM comparison table (2026)
| Provider | Plan | Price | Network | Refund |
|---|---|---|---|---|
| Flysimio | 5 GB / 30 days | $7.50 | EE | 14-day full |
| Airalo (Discover+) | 5 GB / 30 days | $12.00 | EE | Unused only |
| Holafly | Unlimited / 7 days | $13.90 | O2 | 24-hr unused |
| Nomad | 5 GB / 30 days | $9.00 | Vodafone UK | Unused credit |
| Saily | 5 GB / 30 days | $9.99 | EE / O2 | Case by case |
| GigSky | 1 GB / 30 days | $9.00 | Vodafone UK | No |
Which UK carrier does your eSIM use?
The UK has four major carriers: EE (owned by BT), O2 (owned by Virgin Media O2), Vodafone, and Three. EE is the largest with the most extensive 5G rollout — 50+ UK towns and cities. O2 has strong coverage in major cities and is the main carrier for the London Underground. Vodafone is mid-tier nationally. Three has the most competitive pricing for heavy data users but less rural coverage.
| Carrier | Best for | 5G cities | Rural coverage |
|---|---|---|---|
| EE | Overall quality, Scotland, Wales | 50+ cities | Best in UK |
| O2 | London Underground, cities | 20+ cities | Good but patchy |
| Vodafone | General urban use | 25+ cities | Average |
| Three | Heavy data users | 140 cities | Weakest |
Which UK eSIM plan for your trip?
| Trip type | Recommended | Why |
|---|---|---|
| Long weekend in London | Flysimio 3 GB / 7 days | Maps, Tube navigation, social — 3 GB is enough |
| 2-week England + Scotland road trip | Flysimio 10 GB / 30 days | Rural EE coverage is essential; 10 GB for navigation |
| Scottish Highlands hiking | Flysimio 5 GB on EE | EE has best rural UK signal; vital for safety on remote routes |
| Business trip (hotspot for laptop) | Holafly unlimited | Unlimited + hotspot for laptop use |
| Multi-country (UK + Ireland) | Separate UK + Ireland eSIMs | Ireland is not covered by UK eSIMs — it is a different country |
5G coverage in the UK
EE has 5G in London, Birmingham, Manchester, Leeds, Glasgow, Edinburgh, Cardiff, Belfast, and 40+ additional towns. In rural areas — the Scottish Highlands, North Wales, the Dales, Dartmoor — 5G drops to 4G LTE, and in the most remote areas to 3G. For hiking and remote travel, the EE network gives you the best chance of signal on cliff paths, mountain passes, and country roads.
Installing your UK eSIM
- Purchase before you fly — you need Wi-Fi to scan the QR code.
- Open the Flysimio email and find the QR code attachment.
- iPhone: Settings → Cellular → Add eSIM → Use QR Code.
- Android: Settings → Network & Internet → SIMs → Add SIM.
- Scan the code. Installation takes 10–30 seconds.
- Label the eSIM "UK" and set it as your data line.
- Turn off Data Roaming on your home carrier SIM.
- When you land at Heathrow, Gatwick, Manchester, or Edinburgh, your phone connects to EE automatically.
Frequently asked questions
What is the best eSIM for the UK?
Flysimio on the EE network is the best value UK eSIM in 2026 — you get the UK's best carrier at the lowest price. For unlimited data, Holafly is a strong second. Airalo works on EE but charges more for the same plan.
Which eSIM uses EE in the UK?
Flysimio and Airalo both route through EE for UK plans. EE is the largest UK network with the most extensive coverage in rural England, Scotland, and Wales.
Does Holafly work in the UK?
Yes. Holafly offers unlimited data plans for the UK on the O2 network. O2 is strong in London and major cities but falls behind EE in rural Scotland and Wales. For city-focused travel, Holafly's unlimited plan is good value.
Do I need a UK SIM card or can I use eSIM?
eSIM is the better choice for most visitors. It is cheaper than airport SIM kiosks, no SIM-swapping required, and your home SIM stays active for calls. The only reason to buy a physical UK SIM is if your phone does not support eSIM.
Is there eSIM coverage in rural Scotland?
Yes on EE. EE has the best rural UK coverage of any carrier — including signal in parts of the Scottish Highlands, Skye, and Orkney. Remote glens and island interiors may have 3G or no signal, but EE gives you the best chance of connectivity on remote routes.
Does the UK eSIM work in Northern Ireland?
Yes. Northern Ireland is part of the United Kingdom and is covered by UK eSIM plans. Belfast and surrounding areas have strong 4G LTE. The Republic of Ireland is a separate country and requires a separate eSIM or an EU regional plan.