I think one of the top must-have items for travel in Japan is the internet connection on your smartphone. I understand some people want to be offline during vacation. But Japan is still not that international; a lot of people don’t speak English and restaurant menu or signs in public are usually only in Japanese. Also, the trains are convenient but pretty confusing if you are not used to it. For these reasons, I think having a smartphone with you with which you can use to lookup the language as well as the route and timetable of the trains, or to check the google map will be very efficient.

To keep your smartphone online, you need to get a local data SIM card since free wi-fi is not widely available in Japan. In this post, I will explain what you need to know about SIM cards in Japan.

I will first let you know how to find out if your smartphone will work with a Japanese SIM card. Not all smartphones can be used internationally. Some are region locked, carrier locked, or simply does not support the networks used in Japan. Then I will briefly tell you where to get a SIM card and how to use it.


1. Will your smartphone work?

First of all, your smartphone has to be unlocked. Unlocked means it is not locked by a certain network provider such as AT&T, Docomo,  T-mobile, and such. If you buy a device from a provider, it is generally locked unless you have asked to unlock it. Even if you buy a device through retailers such as Amazon, if the device is designed for a certain carrier, then it is locked. Unless the product is specified “unlocked”, they are usually locked.

*There are unlocked iPhones sold at Apple stores and unlocked android devices such as Nexus brand sold on google store. In Southeast Asia, many phones are unlocked.

Second, your smartphone need to be compatible with the networks in Japan. In short, your smartphone needs to be compatible with 3G/LTE(4G) Band 1 (2100MHz) and Band 19 (800MHz). Most prepaid SIM cards you will find in the airports and electronic retailers like Big Camera in Japan use the network of a company called Docomo and they work mainly on those two networks.

Band 1 (2100MHz) is the main band and Band 19 (800MHz) is the sub band. If your device does not support Band 1, it will not work in most areas in Japan, so don’t buy a SIM card. In addition to Band 1, it is better your device supports Band 19 (800MHz) as this covers suburban area. Without being able to connect to Band 19, your device will have spotty or no signal once you are out of the cities.

To find out if your smartphone works on Band 1 and Band 19, you need to check the spec of your device. You can simply google the model number of your device to find that information. For example, my phone is Nexus 5x and the model is as written on the back cover of the phone, “H791”. When i google “Nexus 5x H791”, I can find the list of networks which this device works on. Alternatively, I can find the same information by googling the “IMEI” number of my phone. There are several ways to find the “IMEI” but the easiest will be to dial *#06#, then pop ups the 15 digits. It can be found somewhere under “Setting” menu on your device as well.

Is your smartphone compatible with the SIM cards in Japan? If it wasn’t, consider renting a pocket wi-fi. I will talk about that some other time.


2. Where to get a data SIM card

It has become easier to find a prepaid SIM card for tourists in Japan now. You can get it at the airports or big electronic retailers like Big Camera, LABI, Yodobashi Camera in the cities. If you are not going to be in cities like Tokyo, Osaka, and Nagoya, buy it at the airport. It may be hard to find once you have left the airport. If you are landing late, the shops at the airport will be closed but you can still buy them from vending machines (small airports don’t have vending machines).

Some companies also sell them online where you can order it before coming to Japan, and get it delivered to your hotel or any Japan Post Office in the airport or near the place you stay. This will be a good option if you don’t want to waste your time looking for a SIM card after arriving to Japan.


3. How to choose a data SIM card brand

As said earlier, most prepaid SIM cards use Docomo network, so in terms of coverage, all products are the same. It is said that Docomo has the widest coverage in Japan among all mobile network providers. There are prepaid SIM cards by another company Softbank, but you are required to scan your passport and register for activation and it’s a bit of hassle, so I would not recommend.

The speed may be different depending on the brand but I am not sure about the details. I would say stick to the big companies’ SIM like OCN (NTT) ONE Prepaid SIM for JAPAN , IIJ’s BIC SIM JAPAN TRAVEL SIM, and So-net Prepaid LTE SIM, then it won’t be that bad.

Make sure you choose the correct size of the SIM. There are Regular/Standard, Micro, and Nano. The recent models take Nano size SIM including all iPhone models since iphone 5.

The prices vary depending on the data amount and the valid period. Think about how much internet you will need during your stay. Unless you are going to watch Netflix or Youtube a lot, or upload photos on FB and instagram etc. all the time, you won’t be using that much data. As for the period, the longest period for prepaid SIM is 90 days

Renting a SIM card is also an option. I would recommend CDJapan Rental as their prices are cheap and you can get a refund if your device was not compatible. Also, they offer packages for those who need it for longer than 90 days up to 1 year, so it’s good for those staying in Japan for a while. Although it may be a bit of work to return the SIM card, since they allow unlimited data usage, you can avoid the risk of going completely zero data in the middle of the trip.


4. How to use a SIM card

Now, once you get a SIM card, you have to configure the Access Point Name known as APN on your smartphone. It’s easy.

For android devices, you will create a new APN by entering the necessary information provided by the SIM card brand.

For iPhones, you will have to download the APN profile provided by the SIM card brand. You will need free wi-fi to do this. For older iPhone models, you may need to set the profile manually.

If your smartphone does not seem to get connected to the internet after setting the APN, try these.

  1. For android devices, double-check the APN you created. A single spelling mistake will disable the connection.
  2. For iPhones, the APN profile will not be installed properly unless you download it via Safari browser. Try downloading it again via Safari.
  3. Make sure airplane mode is off, and cellular data/data enable is on.
  4. If your smartphone has 2 SIM slots, take out the other SIM and use only 1 SIM.
  5. Turn on the airplane mode and then off, as this will reset the connection.

Also, if you are using iPhone, remove the APN profile after finish using the Japanese SIM card. The SIM card from your country may not work properly if you don’t remove it.


5. You need a voice SIM?

It’s not easy to get a prepaid voice SIM card in Japan. As of now, I know that there are two prepaid voice SIM cards sold for tourists but both are only sold at the airports. I am not sure if you can find it outside the airports. Check out Wi-Ho! Data&Voice Prepaid SIM by Telecom Square and  JAPAN PREPAID SIM by TRE mobile if you are interested.


To summarize…

Check if your smartphone works with a Japanese SIM. If your device is not compatible, consider renting a pocket wi-fi. The only reason I suggest getting a SIM card rather than a poket wi-fi is the cost; SIM is cheaper. I’m sure having a smartphone with internet connection during your travel in Japan will be very helpful!



Written by mochi-tomo