You step off the plane and open your phone first thing. You pull up the way to your hotel on the map, check your train transfers and send your family a quick “Made it!”
If you can do all that from the moment you land in Japan, the start of your trip feels a lot lighter.
For that, there’s just one thing to decide before you leave: how you’ll get your phone online in Japan.
And what you’re probably wondering most is whether a surprise bill will show up after you get home. This article starts with how to choose so that worry goes away.
Prices and rules can change, so before you sign up, check each company’s information (as of October 2026).
Four ways to get online, with free Wi-Fi as a helping hand
Broadly speaking, there are four ways to get your phone online in Japan.
- Stay on your home line (roaming): keep your usual phone and number, and use your home carrier’s service
- eSIM: put a travel plan inside your phone. No card swapping
- SIM card: insert a small travel card into your phone
- Pocket Wi-Fi: rent a palm-sized Wi-Fi device and carry it with you
On top of these, airports and stations have free Wi-Fi. But since you can only use it in certain places, it’s a helping hand, not the main act.
The answer first — if you’re worried, switch to something made for Japan
- Your home carrier has a plan you can use in Japan, and you know what it costs → roaming. Your usual phone, just as it is
- You’re not confident with settings, or you’re worried about a surprise bill → don’t rely on your home line; switch to something made for Japan. That keeps it simple
- Your phone supports eSIM and isn’t SIM-locked → eSIM (you can add it at home before you leave)
- Your phone doesn’t support eSIM but isn’t SIM-locked → SIM card
- You want to connect several devices with family or travel companions / your phone is SIM-locked → pocket Wi-Fi
To decide which one, start by looking at your own phone.
First, check your phone — SIM lock and eSIM
eSIM and SIM cards only work if your phone is not SIM-locked. If it’s locked, a travel plan won’t work even if you add it.
On an iPhone, go to “Settings” → “General” → “About” and see whether “Carrier Lock” says “No SIM restrictions.” eSIM works on iPhone XS, XS Max, XR and later models. On Android phones, it depends on the model.
If your phone is locked, go with roaming or pocket Wi-Fi. Both work whether or not your phone is locked.
1 Roaming — easy, and the price is up to your home carrier
You keep your usual phone and number, so it’s the option that takes the least preparation.
If you’re asking yourself, “Roaming on my home line or a local Japanese line — which is better?” start here. Even when you’re roaming, what you connect to in Japan is a Japanese mobile carrier’s network. Your home carrier has an agreement with a Japanese carrier that lets you use its network. That’s what roaming is. Travel eSIMs and pocket Wi-Fi use a Japanese carrier’s network too.
So the difference is mainly money and hassle. And whether you can roam, and how much it costs, is decided by your home carrier. Some carriers have a flat daily rate, and some send you an SMS once your charges reach a certain amount. Check your carrier’s page before you leave, and you can use it with peace of mind.
The thing to watch out for is using it without checking. If you’re not on a plan, or if data roaming is left on, you may end up with a surprise bill. Phone apps use data in the background, for things like automatic updates, even when you don’t have them open. Your usage goes up even when you don’t think you’re using anything. And the bill may arrive after you’re back home.
To stop worrying about the bill — don’t rely on your home line
Checking plans is a hassle, or you’re not confident with settings? Then what keeps things simplest is not using your home line in Japan.
The real fix is to swap SIMs. Once you swap in a SIM for Japan, your home line isn’t active for that whole time. You’ll need your home SIM again when you get back, so put it away somewhere you won’t lose it.
If you’re adding an eSIM and keeping your home number too, there’s just one thing to do. Set your home line so it isn’t used for data (turn data roaming off on it). If you leave both the travel eSIM and your home line on, you may be charged roaming fees on your home line. On an iPhone, you can set data roaming separately for each line.
That said, on the travel eSIM you may need to turn data roaming on, as its instructions say. If you turn everything off, you might not be able to connect. It’s only your home line that you turn off.
When you connect through pocket Wi-Fi or free Wi-Fi, too, keep data roaming off on your home line. If the Wi-Fi is weak, your phone may switch over to your home line.
There’s just one thing to remember. Turn data roaming off on your home line, and set up your travel eSIM as its instructions say.
2 eSIM — add it at home before you leave
With an eSIM, you buy a travel plan online and add it to your phone. There’s no card to swap, so you don’t have to take out your home SIM, and you don’t have to worry about losing it.
On an iPhone, you need to be connected to Wi-Fi (or to someone’s phone through tethering) to add an eSIM. So the easiest way is to add it on your home Wi-Fi before you leave. If you forget, you can also connect to the airport’s free Wi-Fi and add it there.
Once you land in Japan, go to your settings and switch the line you use for data to the travel eSIM. On an iPhone, even while you use data on the travel eSIM, FaceTime and iMessage may keep working with your home number. Check the settings and charges with your home carrier.
You choose a plan by the number of days and the amount of data. Some plans advertise “unlimited” data. Whether the validity period starts “when you install it” or “when you connect in Japan” can differ from plan to plan.
Whether you can share it with other devices by tethering, and how much data you’ll need, are covered in the “eSIM” article.
3 SIM card — buy one after you arrive, or get it ready online before you come
With a SIM card, you swap your phone’s SIM for a small travel card. Even if your phone doesn’t support eSIM, it works as long as it isn’t SIM-locked.
You can buy one online before you come to Japan, and after you arrive, you may also be able to buy one at airport counters and vending machines, electronics stores or convenience stores.
On the day you buy a SIM, keep your passport handy. Even for a data-only SIM, some companies ask to check your passport. For example, SoftBank’s SIM for travelers requires a photo of your original passport, and people under 18 can’t sign up.
Where to buy one is covered in the “SIM Cards” article.
4 Pocket Wi-Fi — one device gets everyone online
With pocket Wi-Fi, you rent a Wi-Fi device and carry it around. Your phone just connects to the device’s Wi-Fi. You don’t change SIMs, so it works even on a SIM-locked phone.
Its biggest strength is that one device can get several devices online. Your family’s phones, a tablet, a laptop, all on the same device. Some companies say up to 8 devices can connect.
You can pick one up at counters at airports such as Haneda and Narita, and some companies will deliver it to where you’re staying if you book ahead. Ordering before you come to Japan is often cheaper. When it’s time to return it, some companies let you drop it in a Japanese mailbox.
The trade-off is a little extra effort: carrying it, charging it and returning it.
How to rent and return one is covered in the “Pocket Wi-Fi” article.
eSIM or pocket Wi-Fi?
The most common question is which of these two to go with.
- If you’re traveling solo, or each person connects on their own phone: eSIM. Nothing extra to carry, and nothing to return at the end
- If several of you share one device, you also want to connect a tablet or computer, or your phone is SIM-locked: pocket Wi-Fi
Still not sure? The “eSIM, SIM Card or Pocket Wi-Fi for Japan?” article gives you just the answer first.
Arriving late at night? Sort it out before you leave
Airport counters have opening hours. At Narita Airport, the counters are open roughly from 7 a.m. to around 9 p.m. Haneda Airport has counters open from early morning until around 11 p.m., and Terminal 3 also has a 24-hour unstaffed Wi-Fi rental.
At Narita, the counters are outside security and customs (in the area anyone can enter).
Even so, if your flight gets in late at night, add your eSIM before you leave or have your pocket Wi-Fi delivered to where you’re staying, and you won’t have to look for anything at the airport.
Rough prices
As for SIM card prices, GO TOKYO says they’re roughly between ¥2,000 and ¥8,000 (page updated September 1, 2026).
Prices vary a lot depending on the number of days, the amount of data and the company, so check each company’s page for its prices when you sign up.
Free Wi-Fi — no sign-up needed at the airports
The free Wi-Fi at Haneda Airport (HANEDA-FREE-WIFI) and Narita Airport (FreeWiFi-NARITA) can be used without signing up. You can count on it if you forget to add your eSIM, or when you want to message your family right after landing.
Stations, tourist spots and some shops also have free Wi-Fi. But how you sign up differs from place to place, and the connection ranges from good to patchy. If you install an app called “Japan Wi-Fi auto-connect,” you sign up just once and it connects you automatically to free Wi-Fi at airports, stations, shops and more.
In rural areas, places with free Wi-Fi are even more limited. It’s hard to get through a trip on free Wi-Fi alone, so it’s realistic to think of it as a helping hand.
Also, some free Wi-Fi isn’t encrypted. Narita Airport recommends using a VPN if you want a secure connection. For more, see the “Free Wi-Fi” article.
Do you need a Japanese phone number?
Some travel eSIMs and SIMs are data-only and don’t come with a Japanese phone number.
Some services also ask you to enter a phone number. For example, the taxi app “GO” has you register with a phone number and a verification code. Some people register with a non-Japanese number.
There are also SIMs that come with a Japanese phone number (a number starting with 070, 080 or 090). For these, identity checks at sign-up are required by law, and travelers show their passport. Some companies require you to show the original, or only accept people 18 and older.
There’s one more thing worth knowing. With a data-only SIM, you may not be able to call 110 (police) or 119 (fire and ambulance). If that happens, ask staff at your hotel or a shop, or someone nearby, to call for you. Phone calls when you need help are covered in the “When You Need a Japanese Phone Number” article.
When you can’t connect — in mountains and rural areas, it comes down to the carrier
If you’re heading into the mountains or rural areas, you’ll want to know whether you’ll get a signal. That’s where it matters which carrier’s network you’re using. Japan’s mobile carriers each publish a map of where their signal reaches (a coverage map). au, one of Japan’s carriers, also has a map in English. If you’re heading to the mountains or the countryside, take a quick look at the map for the network you’ll use before you leave, and you’ll feel more at ease.
How to check things when you can’t connect is covered in the “When Your Phone Won’t Connect in Japan” article.
For now, just this
- Before you leave, check your phone’s SIM lock and eSIM support
- If you’ll roam, check your carrier’s plan and prices before you leave
- If you’re worried about the bill, go with a Japan eSIM, SIM or pocket Wi-Fi. Keep data roaming off on your home line
- With an eSIM, add it on your home Wi-Fi before you leave
- On the day you buy a SIM, keep your passport handy
From the day you arrive, your maps, your train transfers and your “Made it!” all work just like they do at home. No worrying about a bill that shows up later.
