Prices in pounds · O2 prices checked 6 November 2026
O2 roaming in Japan vs a travel eSIM
In Japan, O2 uses its O2 Travel prices. Here is what that costs for a long weekend, a week and a fortnight, next to a data-only travel eSIM for the same trip.
Photo: David Maunsell on Unsplash
O2 vs eSIM in Japan: 3, 7 and 14 days
O2’s lowest published option in Japan for each trip length, next to a Graba SIM Japan plan with about 0.7 GB a day.
- 3 days
- 7 days
- 14 days
O2 roamingGraba SIM eSIM
| Trip | O2 | Graba SIM eSIM | Difference |
|---|---|---|---|
| A long weekend3 days | £21.00£7 a day × 3 | £3.493GB, 30 days | The eSIM is £17.51 less |
| A week7 days | £49.00£7 a day × 7 | £5.495GB, 30 days | The eSIM is £43.51 less |
| A fortnight14 days | £98.00£7 a day × 14 | £8.9910GB, 30 days | The eSIM is £89.01 less |
What’s included: O2: unlimited calls, texts and data, at up to 2 Mbps. Graba SIM: data only, prepaid; your O2 SIM stays in your phone for calls and texts. Graba SIM prices are live; O2 prices checked 6 November 2026.
Sources: O2 roaming (checked 6 November 2026). Prices change; check before you buy.
Graba SIM Japan plans: data, validity and total price
Each plan is a one-off price for one eSIM. It starts when it first connects in Japan, and hotspot use comes out of the same data.
Using your phone in Japan
- HND Tokyo Haneda
- NRT Tokyo Narita
- KIX Osaka Kansai
- NGO Nagoya Chubu
- FUK Fukuoka
- Tokyo
- Excellent signal across the city, including underground on the metro.
- Kyoto and Nara
- Good at temples and in the old streets, though very busy spots can slow down at peak times.
- The bullet train
- Signal holds well on the Shinkansen, with short drops in long tunnels.
- Hakone and Mount Fuji
- Good around stations and lake towns; hiking trails are patchier.
- Hokkaido ski resorts
- Niseko and Furano villages are well covered; the back country less so.
Networks our Japan plans use: NTT docomoRakuten MobileKDDI/auSoftBank
- Pocket Wi-Fi means collecting a device, keeping it charged and posting it back. An eSIM lives in your phone and works the moment you land.
- Plans give you data only, with no Japanese phone number. Most restaurants and attractions take bookings online or through an app.
Going further with O2
- South Korea (a combined trip with Seoul): O2 charges Standard rates.
- Hong Kong (a stopover in Hong Kong): O2 charges £7 a day.
What you get for the money
O2 Travel Bolt On
- £7 a day, charged only on days you make a call, send a text or use data. Receiving calls and texts doesn’t trigger it.
- Calls to the UK and within the destination are included; calls to other countries are not.
- O2 Travel starts a 24-hour charge the first time you call, text or use data. Receiving calls and texts doesn’t start it.
Graba SIM Japan eSIM
- 5 plan sizes for Japan, from 1GB, 7 days to 20GB, 30 days, each a one-off price.
- Runs on NTT docomo, Rakuten Mobile, KDDI/au in Japan, with 5G where the network offers it.
- Data only. Your O2 SIM stays on for calls and texts, so bank codes still reach you in Japan.
O2 in Japan: questions
How much does O2 roaming cost in Japan?
£7 a day with the O2 Travel Bolt On: unlimited calls, texts and data, at up to 2 Mbps. For a trip, that is 3 days: £21.00 (£7 a day × 3); 7 days: £49.00 (£7 a day × 7); 14 days: £98.00 (£7 a day × 14).
Is a travel eSIM cheaper than O2 in Japan?
It depends on the trip. Comparing O2’s lowest published option with a Graba SIM plan of about 0.7 GB a day: 3 days, the eSIM is £17.51 less; 7 days, the eSIM is £43.51 less; 14 days, the eSIM is £89.01 less. O2’s price also includes unlimited calls, texts and data, at up to 2 Mbps.
Is an eSIM better than pocket Wi-Fi in Japan?
For most people, yes. There is nothing to collect or return, no extra battery to carry, and it works for one person anywhere they go. Pocket Wi-Fi can suit a group that stays together and wants to share one connection.
Does the eSIM work on the bullet train?
Yes. Coverage is good on the main Shinkansen lines, with short drops in long tunnels. Download tickets and maps before you board as a backup.