Friday, November 25, 2011

Unlocked iPhone using a Docomo Xi LTE SIM card to avoid tethering charges

Update: confirmed at a Docomo shop that a FOMA contract can indeed be converted to a Xi plan, but beware that if you go back to FOMA, you'll pay more for the monthly base fee because the phone is now an "old" phone starting service - it won't be eligible for the "value" plan for "new" phones, only the "basic" plan.
Docomo "Xi" 3.9G LTE microSIM card
A Shukan Ascii article has a detailed description [J] on using an iPhone 4S on Docomo now that Xi micro SIMs are available. Keep in mind that this should work for any phone that supports UMTS-2100, Docomo's primary band.

Previously this was prohibitively expensive because Docomo would automatically levy a tethering charge on all unlocked phones that use 3G "FOMA" service (except the SBM 008Z). However, tethering is ostensibly allowed on Docomo's 3.9G "Xi" LTE because data usage is capped. A non-LTE phone with a Xi SIM card will connect to the FOMA network, so we now have a reasonable option for non-Docomo branded smartphones.


See here and here for a more detailed explanation.
Compared to AU and SBM, this will be more expensive. With a 2-year contract, the standard voice plan is ¥780, but this includes no talk time. 24 hour free calls to Docomo subscribers costs an additional ¥700. Currently, data is cheap, only ¥4,410, but from 5/1/2012, this will increase to ¥5,985.

Monthly price with 2-year contract
Until 4/30/2012
From 5/1/2012
ISP charge
Universal service charge
Talk 24 (optional)
¥6,432 (5,723)
¥7,998 (7,298)

Data Cap

Currently, exceeding 7GB apparently results in a speed reduction to 128 kbps, though has been a point of confusion. From 10/2012, there will be an option to purchase an additional 2GB for ¥2,625.
なお、Xiデータ通信専用プランについては、お客様により安心してお使いいただけるよう、既存のXiデータプランも含めて、全て、7GBを超える通信は自動で送受信時最大128kbps1 とさせていただき、追加料金不要で引き続きご利用いただけるようにいたします。
2012年10月1日からは、お申し出いただいたお客様については、2GBのご利用ごとに2,625円をお支払いいただくことで、7GBを超えた通信でも、受信時最大75Mbps1 の通信速度でご利用できるようにいたします。

Starting Xi Service

Actually getting in and out with the SIM could be a hassle, depending on the quality of the staff you speak to.

First, Docomo does indeed sell ala carte SIM cards for unlocked phones, and it is my understanding that you don't need to actually bring in the phone, which would be a good idea if your phone doesn't display the MIC certification mark. (Unfortunately, some properly certified phones weren't stamped by the manufacturers, like the Nexus One.) Just tell them you are using an unlocked iPhone 4S but don't have it with you. (If you are using an unlocked iPhone 4 or 4S, you can take it in, no problem.)

Next, because Docomo decided to invent names for it's SIM cards, make sure you have your terminology correct. The Xi SIM cards are RED (see image at top) and called ドコモUIMカード AX04 (Docomo UIM Card) for the full size SIM, and ドコモminiUIMカード AX04m for the microSIM.

The staff may be confused as to why you want to use get Xi service when you don't have an LTE phone. Some may even try and tell you that it would be cheaper to get FOMA service. Be firm and patient and insist on Xi. If you're not making any progress, leave, go to another store, and try again. Whatever you do, don't get a WHITE SIM CARD!

Docomo FOMA 3G microSIM card

Thanks to Sven.


  1. I think my dreams of getting a Galaxy Note have just come true!

  2. My friend asked same thing and it's possible to request Xi SIM, even doesn't have LTE phone.
    But the staff warned him, if he want to switch back to white SIM card after May, 2012,
    He won't be able to join "Value plan" again. (I didn't ask the detail)

  3. Do you think you can ask your friend to reply on the details about switching back to the white SIM? He can comment in Japanese if it is easier for him.

  4. Ok, My friend said Xi -> FOMA downgrade is irregular case.
    Value plan includes incentive to buy new phone via docomo.
    If switch back to FOMA, docomo recognizes the phone isn't worth getting monthly discount.
    (Forcibly become Basic plan)
    too complicated, I can't understand the system either.

  5. got one, now just wondering if it has lte on it, cos the website said 3g or lte... do you know?

  6. i got a galaxy note this week and i'm on the bmobile aeon c plan which is unlimited data for c Y5k a month. i guess the note has lte, but the samsung site says region specific which i assume means that if the frequency is right for the carrier then you will automatically be able to use lte.

    so, do i really need to switch to Xi, pay an extra 3k a month for the extra speed? it would be nice, but can't really justify the increase. dang it, hope bmobile can an lte plan...

  7. "A non-LTE phone with a Xi SIM card will connect to the FOMA network" --> When it connects to the FOMA network, wont the non-Docomo phone incur the tethering charge?

  8. No, because your contract is for Xi, not FOMA. Your contract allows you only 7 GB but also allows you to use that for tethering.

    The network that you are using isn't what matters. It's your contract. Or I guess you could say , your SIM card color. Red SIM cards get free tethering but only 7GB. White SIMs get unlimited GBs but expensive tethering.

  9. Actually, I understand what you are saying. In the case of the people who want to use an iPhone for an Android from overseas, it won't be so much of an issue because they won't want to revert back to FOMA, since they can't use the non-Docomo-branded phone.

    Thanks for checking into this!

  10. Unfortunately he can't join here, but he did pre-order Galaxy Nexus at docomo shop.
    I hope I will report the detail from him.

  11. My new Galaxy note will deliver in the next few days.
    Any one used Xi Sim card on it?

  12. please let us know how it works out if anyone has a xi on the note.

  13. So if we had an unlocked phone (sim unlocked) and a tablet which was not sim-locked, then we could get one sim from docomo and use it in either device (assuming Xi/LTE radio is onboard)? Or do they require IMEI locking to one device at contract time?

  14. Am i right in thinking all these will still require a minimum 2 year contract? That the only pay as you go option remains b-mobile?

    PS/ are there any decent options for free/cheap wi-fi around tokyo?

  15. The LTE appears to be region specific, so I doubt it will work with Xi, which is using a 1500 MHz band (though not the exact same one that LightSquared is using in the US that is directly adjacent to the GPS band).

    So the question is, where did you buy it and what are the LTE frequencies of the supported carriers in that region. If it isn't the same as Xi, then it won't work (unless LTE radios are multiband, which I haven't heard of).

  16. Xi SIMs are not IMEI locked to any particular device. You can put it in whatever you want. They use the mopera dot net APN, which is open for anyone. Connecting to the mopera dot net APN with a FOMA SIM automatically adds the tethering charge (recently reduced from ¥4,200 to something slightly less stupid).

    Connecting with an Xi SIM adds not extra cost because it is the Xi APN.

    None of those are Xi LTE.

    EV-DO is CDMA-2000 (Verizon, Sprint, AU)
    HSDPA/HSUPA is enhanced 3G (W-CDMA)
    GSM/GPRS is 2G
    EDGE is 2.5G

    PS - check out some of my xperia posts if you haven't, I have an xperia running a 2.3 ROM right now. It makes a big difference, but the xperia will never be as good as a nexus one, even though they have the same chipset. My experience with that phone has made me weary of anything branded "xperia". I assume (and hope) SE's later phones got better, and it will be interesting to see if things get better or worse since Sony bought out Ericsson.

  17. Check the title on the table. I didn't mention explicitly in the text, but these prices are all with 2-year contracts. Without a two year contract, it is too expensive IMHO. It would be better to bite the bullet and pay the FOMA tethering charge, which has been reduced by about 2000 yen to just under 8500 per month (data only - no voice charges).

  18. Do you know how much it is without a 2 year contract or how much the fee is to cancel it during the contract?
    The prices above seem attractive for my case, as my current SIM free allowing Softbank contract is like 7400 minimum per month now. Add another 1000 when I do a few calls to docomo or after 9 PM.
    I'm using a European Galaxy S (1) now, but I'm thinking of upgrading to some LTE SIM free device next year... I wouldn't mind paying less and get better network coverage already.

  19. ht-03a→atrix tokyoNovember 28, 2011 at 2:52 PM

    Woah, big news with a big effect on my ongoing "Android Phone Usage with Docomo" saga...
    Wondering if this will work:
    1. Bring in my Docomo FOMA SIM card that was originally provided when I started a contract with HT-03A; note: I've currently cancelled the 3G data plan - only paying docomo for phone service
    2. Ask to convert my FOMA plan (which, notably, doesn't exist at the moment, start it up again first?) to the Xi plan because, yeah, the unlocked "iPhone 4S" I don't really have wants to have an LTE card just "because" / "for fun"
    3. Try it out in with my unlocked, non-Docomo branded Motorola ATRIX and then...
    A. If it works on all fronts (as a phone, as a data receiver at reasonable speeds, allows me to tether to iPad) - Cancel my WIMAX plan
    B. If it doesn't work on any of the above fronts, bring it back and get my old FOMA card back?

    Any ideas / advice?

  20. This is what I plan to do. But I realize that you can't say for a iPhone 4S because you'll get a microSIM and fart around with an adapter.

    Saturday, I took in my ht-03a, which also has no data plan. I said I wanted to convert to Xi and use it on this ht-03a. The lady looked a bit confused but said she would check if it was possible. It is possible. She also noted that I didn't have a data plan at all.

    I showed her the n1 and said it was using bmobile. She agreed that bmobile was a good value.

    I said I want to start using the ht-03a again, but with the Xi SIM. No problem

    I also said would it work if I instead put the Xi SIM in this nexus one, and she said yes. She didn't ask about MIC cert.
    I'd then suggest taking in you ht-03a and say you want to convert the SIM to Xi. If you don't have the ht-03a, just go in with nothing. They are going to have to press a new SIM anyway. Just say you don't have the phone but want to upgrade.


  21. Double the basic fee - looks like data doesn't change

  22. ht-03a➡Atrix TokyoNovember 28, 2011 at 10:09 PM

    Thanks for the reply...yeah, I may wait to see how it goes with you...I Appreciate your willingness to try it out and then feedback on how it goes!

    I know one thing for sure, I think it is a good idea to start mixing up with shops I go to...while the staff there re untrained and really have no idea what to do, it seems like it is a good idea to have people who are "fresh" with the topics at hand help you.

    Funny side note: my Atrix broke (ear speaker went silent) and has been with Motorola USA repair (terrible place to deal with, reiteration of how amazing customer service here in Japan is)'s on it's way back here now but I've actually been using my ht-03a for my phone for the past month. More fodder for my wife to tell me: "I told you do." She is right.

  23. ht-03a➡Atrix TokyoNovember 28, 2011 at 10:14 PM

    I wonder if upgrading to the Xi sim means entering into another contract....

  24. Hi, I just stumbled across this web page since I've been debating how to get my unlocked iPhone 4s onto Docomo's Xi service. I did read through the ascii posts regarding how they did it. I'm just wondering, is this a loophole in the system or has Docomo thought about folks getting the Xi service to enable iPhone's and other non-Docomo 3G phones on their network.

    The thing that I worry about is that the Docomo rep I talked to in the store (I'm native Japanese) kept insisting that regardless of which plan I took (3G/FOMA vs Xi), I would have to pay substantially more (ie the 8,190yen or even more under Xi since its a non-Docomo phone). I'm a bit hesitant to take the plunge since I don't want to be surprised with a huge bill and cancelling the whole plan costs 9,975yen

  25. Wow, still rocking the HT-03A. This was one of the most frustrating phones I ever used (and still own) as it's abysmally slow.
    Looking forward to your report about switching to the Xi plan as 'LostInTranslation' raised some concerns. My Docomo contract period will end this month and I am up for renewal. If the Xi conversion works at the pricing indicated by acsii, I'll probably also go for Xi. If not, b-mobile's Talking Fair will be my choice.

  26. Bernhard,
    if you do the math and compare the two options A) 2-yr contract and B) Std. contract, you will see that option B will only be cheaper if you cancel the contract within 1 year. 12 months will be break-even and from month 13 option A (2-yr contract) will be cheaper.

    How did I calculate?
    Option A: 780 Yen/month + 4,410 Yen/month for data; 9,975 Yen cancellation fee
    Option B: 1,560 Yen/month + 4.410 Yen/month for data; No cancellation fee.
    Assumption is that in case of contract cancellation of the 2-year plan, you would not pay the cancellation fee, but only cancel the data option. Hence, the monthly cost would be reduced to 780 Yen and you let the contract run out.
    If you signed up for 2-yr contract and decided to pay the cancellation fee of 9,975 Yen, plan B would be cheaper until month 12.

    To cut a long story short, if it's very likely that you will cancel the contract within 1 year, option B would make sense.

  27. So if i bought a DoCoMo LTE phone I can tether for free (up to 7Gb) and be able to swap the simm to a new non DoCoMo handset ?

  28. It appears so. I've been doing it for 3 days now (see my G+ page). I am waiting until I sort out a few more things before I post on it. So far, I have had no problems.

    You don't even need to buy an LTE phone, as it seems from this article.

  29. I have a Samsung Note but it's a bit large but a SGII LTE would be just right I think just a pity about the screen nor being HD

    Like the nexus but the lack of SD card and the brain dead placement headphone has put me off and it's not LTE

    Just want to get off Softbank and ditch my EM Mobile account

    How much extra would it be to get a SGII LTE per month do DoCoMo offer a discount like SoftBank ?

  30. yeah, there is a bit of a discount for new contracts, but nothing like what we see in the US or Europe (with a 2-year contract), I think. Best to head down to a shop and check it out, I think.

  31. I think I have found my new phone the LG L-01D it's got the same CPU as the Samsung but the better HD screen

  32. Greetings!
    Do I get it right that if I want to switch my unlocked SBM branded HTC Desire to Docomo (because I need their reception in the mountains), I could get the Xi SIM card and, due to my phone's incapabilities, I would only be able to use the FOMA connection (and pay 8k yen for tethering)? If it is so, is there any difference between Xi and FOMA plans? Or are data plans for FOMA 3G connections that different between Xi and FOMA plans?

  33. Partially correct.

    Yes, your phone will be limited to using FOMA because it lacks an LTE radio, but you will NOT be charged a tethering fee because you'd have an Xi contract. Only FOMA contracts pay the fee because FOMA is unlimited. Docomo doesn't care if you tether on Xi because after 7 GB you get throttled. There is no danger from their point of view of you using more than your fair share of data.

    However, using Docomo might not help you in the mountains if the SBM Desire doesn't have a radio that supports 800 MHz.

    My Nexus One has a T-Mobile radio and no signal out in the mountains because it lack 800. In fact, you'd maybe get worse reception with Docomo because SBM has no choice but to extend the 2100 MHz coverage, where Docomo is relying on 800 MHz to get better coverage for a lower number of towers.

    AFAIK, Docomo is the only carrier in the world to have 800 MHz. So, other carrier's phones are unlikely to support it. The ones that do is often because they support 850 MHz and the radio is able to also pickup the 800 MHz signal. This is apparently hit or miss. The iPhone picks up 800 MHz but the Nexus One doesn't.

    If you are unsure, try a Docomo SIM from a friend. If you have a custom ROM, it will most likely have Docomo's APNs, so you'd want to shut off data or your friend will get charged a tethering fee. Do you get more bars/stronger signal with the Docomo SIM or not...
    Not sure which of these are yours, but this indicates 900MHz, so it won't help you if you stick with the Desire.

  34. Thank you for the reply, it all makes sense. My phone is the first of the two links you posted, and its cellular/data capabilities exactly match those of one of my friends' Docomo phone Sharp SH-12C ( And sure enough, he enjoyed nice reception where I didn't.
    But it's anyway a good idea to first try his SIM without data first to make sure.

  35. So is voice only ala carte to non-docomo customers, or is there a way to add monthly minutes?

  36. No minutes in plan. No possibility for minutes in plan. Best to use a VoIP alternative like skype or something for calls to non-Docomo peeps.

  37. Thanks for the quick response. I'll look into Skype and Viber then. Thanks again!

  38. Am I the only one who is incredibly annoyed by the whole japanese system? It is C-R-A-ZY:

    - Incompetent staff who will willingly give wrong answers.
    - Incompetent staff who will tell you "This is impossible" when it REALLY IS.
    - Having to go to 5 different shops before you find someone who is actually willing to help you.
    - Having to pay megabucks for the right to use your legally unlocked phone.
    - (true story) going to a Ntt Docomo branch and being told by the branch manager that your gaijin card LOOKS FAKE! I felt so embarrassed, they made me feel like I was a criminal.
    - Having close to no perks entering a 24 months contract compared to any EU/US countries.

    Gah. I've had it with this nonsense.

  39. This is the exact reason why this blog exists :)

  40. This being said, today a MIRACLE happened.
    I went into my Nakameguro branch where i spoke to a certain Natsumi (her name deserves to be mentioned as she was a real angel) She knew everything about the whole Xi to unlocked phones from overseas deal, put me through a very professional guy at the other end of the phone who then talked me through the whole pricing thing etc etc.

    Whenever my japanese fell short (I do admit I have issues whenever they start talking about "certification insurance" or whatnot) he would switch to beautiful english.

    I was grinning all the way home, now all I have to do is to bring my Iphone to the branch as they are already all briefed and now what i expect/need.

    A miracle a tell you. Free, independent thinking from too NTT Docomo employee in succession. I bet this has never happened before lol.

    This blog is hilarious btw. ;p

  41. Quick question regarding this article. Any pros for subscribing to the LTE Xi ninen contract VS the Foma one? Seeing that Iphone 4s doesn't support LTE?


  42. It's a good that you're looking into your options now so that you can cancel during that one month every two years. I've never really looked much into emobile because of their frequencies - makes it hard for people to come over and use their service. US T-Mo phones would be OK, but anything from EU or Oz wouldn't.

    Lately, emobile is looking pretty good - relatively fairly priced indeed.

    I assumed the x10 supported infrastructure mode, since it is essentially the same hardware as the nexus one. I just turned on tethering from the built-in server and it was infact adhoc. That sucks. x10 is an abomination of a phone that should have been aborted.

    I am really liking this Xi SIM. I am using it in no capacity that I couldn't use a FOMA SIM. Only difference is the monthly price, since I'm using a non-docomo phone. But I don't worry at all about tethering, since it's allowed, and am also using the native SIP client with my US VoIP service. All working pretty much flawlessly. Absolutely amazing for a 2 year old phone.

  43. I don't really phone, I prefer texting. ;)
    So Xi looks like the better deal for me. Thanks a lot for the advice and comments guys. ;)

  44. If by texting, you mean SMS, don't use that in Japan since there are free alternatives.

    Instead, use email, like you gmail account or if you have sp-mode, your account.

    if by texting you mean sending email from your gmail account, etc., then ignore this message.

  45. I meant both the free alternatives lol. Sp mode texts and sending mails. I've always found that my japanese isn't too good when on the phone, I mistake some sounds for others... It's good training though.
    Thanks again. ;)

  46. Hey my name is James. I currently use a Galaxy Note SC-05D (before i used the sim free note but got tired of paying for the foma at 8100 per month) I looked at my current APN settings that I have been using since i got this phone and its running on the SP Mode APN. If I use a sim free device with my Xi card will i have to change my ISP to MoperaU? Or with the SP Mode APN + Xi Sim bypass me around that retarded IMEI blocklist?

    Thanks in advance. email is if you prefer to answer in private.

  47. Not really sure about sp mode. You won't incur any charges, so you can always just try and see what happens. You can also just try manually using

  48. Hi all - eoncouraged by this site I took my unlocked iPhone 4S to Docomo today and signed up for Xi package - voice + data - for 2 years. Voice is working fine, but cannot for the life of me get past the "initial setup" page on So I have no 3G. I know Docomo is going to refuse to help me as they dont support iPhones...
    I connect the phone to Wifi at my work, then navigate to (as instructed by the welcome SMS I received). Once there I enter my network PIN (which I set up in the Docomo shop) and click on "I agree". Then the page hangs. Every time. All other websites are working fine on the phone.
    What am I doing wrong?