Japan SIM, eSIM or pocket Wi-Fi? What to buy before you fly and where to pick it up

An eSIM is a digital SIM built into the phone. Apple sums up the travel advantages: nothing to collect, carry or swap, no card to lose, and on supported iPhones two eSIMs can be active at once, so your home number stays on one line while a Japanese data plan runs on the other. Short plans are inexpensive: JAL ABC, for example, sells a 3 GB eSIM valid for seven days for ¥2,700 at its Narita and Haneda Terminal 3 counters and in its online store. The catch is setup. JAL ABC notes that activating an eSIM needs Wi-Fi or another internet connection, so install it at home or while you're still on airport Wi-Fi.

A physical prepaid SIM works in any unlocked phone with a SIM tray. AnyFone JAPAN, the visitor brand of SoftBank's official rental partner, sells data-only prepaid SIMs on SoftBank's network, from 3 GB for five days (¥3,960) to 50 GB for 90 days (¥9,900). The cards are multi-size (standard, micro and nano) and can't be topped up, so choose a plan with some headroom. You'll need a SIM pin to open the tray, and somewhere safe to keep your home SIM while it's out.

A pocket Wi-Fi router is a small rented hotspot that several phones, tablets and laptops can share, which suits families and groups. JAL ABC's 4G router costs from ¥1,050 a day booked online (¥1,313 at the counter), with no separate rental fee, and a 4G/5G model from ¥1,584 a day online. It is one more device to charge and carry, it has to go back at the end, and JAL ABC warns that very heavy use in a short time — streaming video, video calls, large downloads, online games — may be restricted.

Most travel plans are data only, so you won't get a Japanese number for ordinary calls; messaging and calling apps work over data. If you need one, JAL ABC also sells a data-and-voice SIM (5 GB, ¥8,900 for 15 days or ¥9,900 for 30) for domestic outgoing calls only, listed at 10 minutes per call. Treat free Wi-Fi as a back-up rather than a plan: SoftBank's FREE Wi-Fi PASSPORT gives visitors two weeks of free access at its hotspots, renewable with a new password, but it asks for your mobile number, may not be available on some contracts such as prepaid ones, and isn't encrypted.

A Japanese SIM or eSIM only works if your phone isn't locked to your home carrier. Apple's check for iPhone: open Settings, tap General, then About; if the phone is unlocked, 'No SIM Restrictions' appears next to Carrier Lock. If it doesn't, ask your carrier to unlock it well before the trip.

For an eSIM you need an iPhone XS, XS Max, XR or later. Apple says the iPhone must be connected to Wi-Fi to activate one (in some countries eSIM-only models can do without), and that, depending on local regulations, you may be asked to show identification such as a passport when you buy. With iOS 26 or later, a travel eSIM bought before you leave can prompt you to 'Turn On Travel eSIM' when you land, and the phone switches back to your home line when you return, depending on your country or region.

On Android, Google says Pixel 3a and later phones can use one physical SIM and one eSIM together, Pixel 7 and later can run two eSIM profiles at once if the carrier allows it, and a Pixel 3a bought in Japan can't use two SIMs. On other phones, look for an eSIM option in the network settings or ask your carrier.

The simplest alternative is to roam on your home plan. Apple suggests checking whether your carrier includes international roaming at no extra fee on some plans, or sells travel passes you can buy ahead. It keeps your own number with nothing new to set up, so compare its price with a local eSIM or SIM before you buy.

At Narita, the airport's official list shows phone, Wi-Fi rental and SIM counters in all three terminals, all of them before departure passport control and most open 07:00–21:00. JAL ABC's 1F counters in Terminal 1 (North and South Wings) and Terminal 2 open at 06:30 and stay open until an hour after the last international arrival. SIM-card vending machines stand in all three terminals, including several on Terminal 2's 2F before customs, and Terminal 3 has a J WiFi & Mobile counter (07:00–21:00).

Haneda has counters for international arrivals in both Terminal 3 and Terminal 2. In Terminal 3's 2F arrival lobby, Telecom Square's Mobile Center is open 06:30–23:00, with a 24-hour unmanned Wi-Fi rental point in front of it, and the AnyFone JAPAN counter is open 06:00–23:00. In Terminal 2, J WiFi & Mobile / GLOBAL WiFi has a counter in the 2F international arrival lobby (05:45–23:00). AnyFone JAPAN SIM vending machines in Terminals 1 and 2 run 05:00–24:00.

Kansai copes well with late arrivals. Its official list includes GLOBAL WiFi pick-up lockers for routers (the north lockers are open 24 hours), SIM-card vending machines from GLOBAL WiFi and JTB (JTB's is open 24 hours) and Telecom Square's unmanned WiFiBOX machines at international arrivals, also open 24 hours. With WiFiBOX you book online, receive an e-mail with pick-up instructions three or more days before your pick-up date, then scan the QR code on the machine with your phone and the router pops out. You'll need the pick-up page open on your phone, and JNTO notes that Japan's major international airports offer free Wi-Fi in the terminals.

Book ahead wherever you can. JAL ABC's online deadline is 17:00 Japan time one day before pick-up at Narita, two days before at Haneda Terminal 3 and three days before at Kansai, where reservations are mandatory and the pick-up counter is in the Terminal 1 departure lobby. Walk-in rentals depend on counter stock, and staff check your passport (or other ID) and a credit card when they hand over a router.

If you'd rather not queue on arrival, several rental companies deliver. Sakura Mobile says it ships to any hotel in Japan so you can start using the device when you check in, and asks you to confirm in advance that special pickup locations can receive your package. Japan Wireless lists hotels, airports, post offices and private residences in Japan as delivery destinations, and says your router should arrive before your rental start date, barring last-minute orders or delivery delays. Yamato Transport notes that some inns don't accept guests' parcels or limit where and when they can be collected, so e-mail a ryokan before choosing delivery there — our guide to delivery to your ryokan explains the address format and timing, and our guide to ordering before you arrive covers having other things waiting at your first hotel.

Returns are often by post. Sakura Mobile and Japan Wireless include a prepaid return envelope that goes into any Japan Post postbox; Sakura Mobile asks you to pack the router and every accessory in it. Sakura Mobile points out postboxes at all Lawson convenience stores and at major airports, but none after the security or passport checks, so post it before you go through. SIM cards don't go back; Sakura Mobile says to simply dispose of them after use.

Other companies use boxes and counters. A WiFiBOX router (5G models excepted) can go back into any WiFiBOX machine with a free slot, at an airport or a station, not only the one you booked. JAL ABC takes routers back at its departure-lobby counters at Narita and Haneda Terminal 3 and, at Kansai, at its Terminal 1 arrival-lobby counter, and Kansai also has a 24-hour JAL ABC return box.

Late returns cost money. WiFiBOX charges one day's rent for each day past the return date and a ¥15,000 fee if the router isn't back within seven days without notice; you can extend online, up to 180 days from the pick-up date. On a ryokan trip, allow a day's margin if the nearest postbox or return point is a bus ride from your inn.

JNTO advises against expecting traditional ryokan and smaller minshuku to provide Wi-Fi, especially in the mountains or the countryside, suggests checking when you book, and recommends Wi-Fi rental for guaranteed access in remote areas. Our ryokan reports show what that looks like. At Kanaguya in Shibu Onsen, Wi-Fi works only near the front desk and lobby. Nasu Kogen no Yado Sansuikaku has Wi-Fi in the lobby and lounge, and the inn's facility page says not in the rooms. At Naruko Onsen Kanshichiyu, the cheapest Type C and D rooms come without Wi-Fi.

Weak inn Wi-Fi can matter at dinner, too. At Hatcho no Yu, deep in Okukinu, drinks are ordered by QR code, and one guest couldn't use it on the weak Wi-Fi. Elsewhere in Okukinu, at Kaniyu, in-room Wi-Fi is weak but the three main mobile carriers work, which is exactly where your own SIM, eSIM or router earns its keep. At Sumiya Kiho-an, in the hills outside Kyoto, it's the other way round: mobile signal is weak indoors, but Wi-Fi is available.

Networks differ as well. At Tsurunoyu in Nyuto Onsen, our report says mobile signal is patchy, with au and SoftBank especially affected, while Wi-Fi works in the lounge. Every prepaid SIM and rental router runs on a particular carrier's network — AnyFone JAPAN's SIMs, for example, use SoftBank — so before a trip to a remote valley, check which network your plan uses and ask the inn which one works there.

A few inns have no mobile signal whatsoever, and nothing you buy will change that. Yachi Onsen in the Hakkōda mountains has no mobile signal anywhere; free Wi-Fi is officially at the front desk, in the lobby and in parts of the restaurant. Lamp no Yado Aoni Onsen has no mobile signal, TV or internet, and our report warns that emergency calls may not connect. Before heading to places like these, download offline maps, bus and train times and your booking details, and let someone know your plans.

Some inns help out. Kinugawa Onsen Hana no Yado Matsuya, where mobile signal and Wi-Fi are weak in parts of the building, lends pocket Wi-Fi at the front desk, so ask at check-in before you assume you're offline.

Whatever connection you have, the phone stays out of the bath. JNTO's onsen guide says to leave your phone outside the bathing area and calls taking a phone or camera into an onsen absolutely forbidden, out of consideration for others' privacy, particularly that of children. Leave it in your room safe or a changing-room locker; a waterproof pouch is still useful on the walk to an outdoor bath in rain or snow.

A day of maps and translation drains a phone, and a router adds a second battery to keep charged. JAL ABC rents a compact portable charger alongside its routers for ¥213 a day; otherwise, pack your own power bank. If you've left a charger or cable at home, our guide to replacing a forgotten phone charger in Japan covers where to buy one.

Power-bank rules tightened in 2026. Japan's transport ministry (MLIT) applied new rules from 24 April 2026, following an emergency revision of ICAO standards: at most two power banks per passenger in the cabin, each 160 Wh or less, and no charging the power bank or charging other devices from it on board. Power banks remain banned from checked baggage. Kansai Airport adds that you should tape over the terminals or keep each one in its own case, keep it with you rather than in the overhead locker, and check your airline's website, as rules may vary.

For sockets, JNTO says Japan uses 100 V AC throughout, at 50 Hz in the east and 60 Hz in the west, and the Embassy of Japan in Singapore notes that flat two-pin plugs are generally used. Dual-voltage chargers only need a plug adapter; other devices need a step-down transformer. A charger with several USB ports lets one socket charge your phone, router and power bank overnight.