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Smartphones in Japan: How To Buy, Unlock and Change Plans

Japanese mobile service is notoriously convoluted. Here's what to do if you plan to bring a phone over from home or sort yourself out with a new one while you're here.

By 10 min read 6

A lot has changed in the mobile phone landscape in Japan over the last few years.

Cell phones used to be very heavily restricted. You had a choice of three large companies, all offering near-identical packages and prices, with customer service standards that generally fell well below what you would come to expect from Japan.

To make matters worse, it was nearly impossible to bring a phone into Japan and use it on one of these networks. If you didn’t buy one of the company’s phones on an overpriced two-year plan, then you couldn’t get access to its network.

Thankfully, this all changed a few years ago, when the government brought an end to the restrictive practice that was the blanket ban on phone unlocking in Japan (the process of making a device capable of working on any carrier network). That being said, figuring out the best option for a phone in Japan is still extremely tricky.

In this quick guide, GaijinPot will walk you through the following topics:

Unlocking your Japanese smartphone

After May 2015

Now, any phones bought after May 2015 can be unlocked provided you have been with the carrier for more than 180 days. Some carriers may try to play dumb in this regard. But it is the law, and they cannot refuse to unlock your phone provided you meet these conditions. A phone that has been unlocked should, in theory, work on any network worldwide.

However, bandwidth differences mean that you may not get full functionality. For example, a phone that gives 4G coverage in Japan may only give 3G coverage elsewhere and vice-versa. A number of phones will not work at all outside of Japan, but these days the number of phones with this problem is small and continues to drop year by year.

Be aware, the three main network providers—AU, SoftBank and Docomo—will straight up lie to your face about this.

So, unless you’re very unlucky, unlocking is a great way to free up your options for pursuing cheaper phone plans.

Of course, if you’re planning to cancel your current contract then you will need to pay off whatever amount remains to be paid on the phone too, plus any cancellation fees.

However, you do not necessarily need to cancel your contract in order to unlock the phone. For example, a friend of mine was going home to England for a month during the summer and he wanted to use a local pay-as-you-go SIM card. He unlocked his phone but continued to use SoftBank until his contract ran out some six months later. (This may only be an option depending on your contractor, so do look into that.)

Before May 2015

A common question I am often asked in this regard is: “If my phone was bought before May 2015 can I still get it unlocked?”

The answer is: “Officially, no. Unofficially, possibly.”

Be aware, the three main network providers—AU, SoftBank, and Docomo—will straight up lie to your face about this. They will say it’s impossible to unlock any phone bought from them before May 2015. This is demonstrably false, as I have personally used two different unlocked phones in Japan bought from Docomo and AU prior to 2015.

However, you’ll need to go to an unofficial source to get these phones unlocked. With a bit of internet searching, you will find companies able to accommodate you.

If you can do without your phone for a week or two then the cheapest option would be to send it away to one of the dozens of phone unlocking companies based in Hong Kong who will unlock and root your phone for a fraction of the prices charged in Japan.

The legalization of unlocking is just one positive aspect of the new laws coming into effect.

The difference between “SIM-free” and “unlocked”

In principle, SIM-free phones and unlocked phones function in the same way. They should work on almost any network worldwide. However, there is a subtle difference between the two.

SIM-free, also sometimes referred to by vendors as “factory unlocked,” means that the phone is designed to be used around the world by whichever network you choose. These phones, if they are genuinely SIM-free, should not have any network markings (such as an AU or SoftBank logo) on them. Unlocked phones are those which originally belonged to a specific carrier but have been manually unlocked by someone with the requisite expertise. Although in most cases these phones should work on almost any network, they are less reliable than true SIM-free phones that are designed to be used in several different countries on multiple networks.

Most modern, name-brand phones from abroad will work in this regard. Until recently, I used an iPhone 6 bought in the U.S. and I have heard from friends who used Samsung, ASUS and HTC phones from Hong Kong and Taiwan without any issues.

However, if you have a phone that is perhaps 10 or more years old, it may not work in Japan. Until the mid-2000s, the most common network band globally was GSM, however, Japan has never had a GSM-compatible network. So, GSM phones will not work in Japan.

Do’s and don’ts for switching to a cheaper network or plan

Another encouraging side effect of this change has been the rise of mobile virtual network operators (MVNO). These are companies that rent the existing network architecture from the big three and given lower overheads, can offer far cheaper prices to consumers.

But, to make use of these networks, you will need a SIM-free phone—again, a phone that isn’t locked to any particular network.

One important caveat here concerns AU and the MVNOs using its network that may have compatibility issues with phones from abroad or those native to another Japanese network.

This is because AU’s network uses a different frequency for its LTE signals. In all honesty, it’s probably best just to avoid using AU and its partner networks if you’re bringing a phone from abroad. The Docomo and SoftBank MVNOs have far less potential for compatibility problems and aren’t any more expensive.

Another good option for local MVNO coverage is Line Mobile. As an offshoot of the popular messaging app, Line Messenger, Line Mobile offers data and call plans at very competitive rates as well as numerous bonus features for users of the app.

Actually, if you are a regular user of Line, then going to an MVNO outside of the big three networks can be slightly problematic. This is one of the few drawbacks to switching to an MVNO.

Options for short-term use

As for short term visitors, there are a number of rental or pay-as-you-go phone and SIM options available. Services like Sakura Mobile and JP Smart SIM provide short-term or non-binding contracts specifically geared towards foreign customers where contract termination fees are waived and/or you can use an international credit card. Another popular provider is Mobal.

Finding a SIM-free smartphone

Let’s say your provider is being obstinate and won’t unlock your current phone, or perhaps you are new to Japan and not sure where to even start with this whole phone business.

If you can afford the initial outlay, I strongly recommend getting hold of a SIM-free phone before you go about trying to get a SIM card or contract. This doesn’t just give you greater options in terms of networks, but it also makes it a lot easier for you to walk away and cancel a contract if the provider doesn’t meet your expectations.

So, where can you get a half-decent and reasonably priced SIM-free phone?

  • Facebook Groups

    Facebook is a good place to start, especially if you live in the larger cities. Have a search for local “Sayonara Sales” groups. Foreigners leaving Japan often sell their wares before they depart and phones often feature prominently in the listings. Seeing as you are buying directly from the owner there is also scope for negotiating your own price, depending on how cheeky you want to be, and how desperate to shift the item the seller is. Watch out for deals that seem to be too good to be true. Be sure to check the profile of the seller to make sure it’s genuine before you meet them, and of course, avoid like the plague anyone who isn’t local or who only wants to send items by post.

  • Amazon Japan

    A safer—and in many cases cheaper—option is Amazon Japan. Amazon has an excellent selection of phones in the ¥15,000 to ¥25,000 range that is truly SIM-free, and have all the features one would expect from a smartphone. If you don’t mind going second hand, you can save even more.

  • eBay and Yahoo Auctions

    If you’re a bit more confident in your Japanese ability then another good option is Yahoo Auctions. Yahoo Auctions functions in a similar way to e-Bay in that you bid for items, however, the service is only available in Japanese and the sign-up process is rather complex.

  • International search engine

    Wherever you get your phone from, my final recommendation is that before you complete your order be sure to visit: willmyphonework.net. This is an international search engine that allows you to search specific phone model numbers by country to see which networks they will work on. Make sure that you know the exact serial number of the phone you want to order, as even just within Japan there may be several different versions of the same phone.

Do’s and don’ts of buying a SIM-free smartphone to use in Japan

Sadly, the reality is some companies are less than reputable, and one that I would strongly encourage you to avoid at all costs is Expansys. On the face of it, Expansys appears to be selling popular brand SIM-free phones at prices far below the market rate.

However, despite the site being completely in Japanese and clearly targeted at Japanese domestic consumers, many of the phones they sell do not have Japanese language functionality. In addition, they will not function fully on Japanese networks and are in fact not true SIM-free phones, but manually unlocked phones from foreign carriers such as China Mobile that are not designed to work in Japan. Unfortunately, a few friends of mine have been taken in by these scammers and lost a lot of money in the process.

Another place to avoid, simply because of expense rather than a lack of honesty, is the big electronic stores such as Bic Camera, Yodobashi Camera, and Sofmap.

Another place to avoid, simply because of expense rather than a lack of honesty, is the big electronic stores such as Bic Camera, Yodobashi Camera and Sofmap.

These places have a wide selection of second-hand phones available, but the prices are only slightly cheaper than you will pay for a new handset. Amazon has the same items for a fraction of the price.

Final advice

As a reference point, I currently pay ¥3,200 per month for 10GB of data and unlimited SMS and voice calls (provided I finish the call within five minutes). I use OCN, a Docomo-based MVNO.

SIM-free phones, like many aspects of life in Japan, are an area where it really pays to do your research ahead of time. Much like that naive English teacher who leaps at the first opportunity to work in Japan but ends up with a nightmare job because they let their enthusiasm get the better of them, you need to be careful not to instinctively buy up the first phone that you see. Take your time, shop around and see what you can find.

Still confused about cell phone use in Japan? 😖 You can ask people in the GaijinPot community via the GaijinPot Facebook Group.

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  • Milan says:

    I’m living in japan at the moment and I just wondered if I buy a used iPhone 6s in any kind of “book off” and walk in to the provider without contract, do they unlock it for me? I have an OCN contract.

  • ジュリア says:

    I think another important thing to note is that you need a credit card to sign up for service. My friend from the U.K. with a SIM-free iPhone was unable to get a SIM card from anywhere because she didn’t have a credit card! She had to buy a new phone along with a 2-year plan in order to pay in cash.

  • Chysamere says:

    I strongly recommend the shop じゃんぱら in Akihabara for anyone needing a phone in Japan. I got an ex-Docomo Galaxy S5 for a good price in 2016 and signed up with AsahiNet Ansim service (an MVNO) for 1600 yen a month. Not only does the shop have a great selection of unlocked second hand phones from all the Japanese carriers, but it also has some English speaking staff.

  • TJ says:

    Can an unlocked (Verizon) of S8+ such as SM-G955UZKV be used in Japan? It works to make voice calls but no internet even though APN from Softbank are correct. Any ideas? I’ve been considering buying an unlocked (not branded) phone from Samsung US directly, S8+ SM-G955UZKAXAA, to see if this makes any difference.

  • Nilesh Kodre says:

    I used DOCOMO since last two years and I have iPhone 6
    When I asked DOCOMO to unlock iPhone 6 but DOCOMO told me they unlocked iPhone 6s and above
    Is that true ?

  • MD says:

    I bought my iPhone 7 here in Japan in late 2016 at docomo. I want to take it in and ask to have it unlocked but I’ve heard that even now, employees will play dumb about the unlock law passed in 2015. Could you please link to the law so that people like me can have it in our pockets when we attempt this? For someone with very little Japanese language ability, I don’t have much other recourse when the day “sorry we can’t do that”.



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