An iPhone 4 I got in March 2011 in Australia was able to be used with a SIM when I visited Japan in 2011 to 2013. However, when I tried getting a SIM for it in September 2016, the store staff said that that phone was too old to use one of their SIMs.

Is that true, and if so, is it something I can fix for that iPhone, such as upgrading iOS version? It uses a micro SIM, has a model number of MC603X/A (corresponding to iPhone 4), and has a version of 7.1.2 (11D257) which seems to indicate the iOS version.

I'll be going to Japan and Korea this September, and I've got a more recent iPhone as well, but want to take this as a backup.

  • 6
    You should've ignored the store employees and bough the SIM anyway. Most of the time they have no idea what they're talking about. – JonathanReez Jul 22 '17 at 8:05
  • 1
    At one shop, they only had full size SIMs. Guy pulled out a pair of scissors and cut it to nano size. And it worked. – WGroleau Jul 26 '17 at 3:00
  • @WGroleau nano != micro. Otherwise correct. They even have templates you can print out and do it yourself – jwenting Jul 26 '17 at 5:30
  • 2
    Obviously if cutting down to nano doesn't break it, cutting down to micro won't. – WGroleau Jul 26 '17 at 12:19
  • 1
    Every time a tried a SIM card in the UK, they are full size but pre-cut so you can reduce them to micro or nano size without any tools. – gnasher729 Apr 22 '18 at 9:30

In Japan, eConnect lists the iPhone 4 with iOS 7.1.2 as compatible. I surmise that all other technically identical (Docomo-based, data-only) SIMs from other providers should work as well.

| improve this answer | |

When coming into Incheon airport from KIX, I noticed three places selling SIMs.

One appeared to be from a major Korean brand best known abroad for electronics (such as LG or Samsung), though it's possible that the SIM booth was merely next to it. They tried out their SIM on my new phone (iPhone 5S IIRC), and apparently it didn't work, but they had a WiFi router available. Suspecting a scam, or at least a more expensive option, I decided to go elsewhere.

Another place was a convenience store with a large sign saying they sold SIMs. As the store was busy, I decided to avoid it.

I found another booth dedicated to SIM cards and the like, and they were able to set me up. They noticed that my connection had a certain quality when I should have been able to get better (eg 3G vs 4g etc.), and they worked out I had configuration still set up on my phone which was for my Japanese SIM card, and they uninstalled it and got a better connection.

Moral of the story: sometimes one retailer are able to supply something that another retailer apparently couldn't, so consider shopping around.

| improve this answer | |

Is it possible they just didn't have a larger sim card anymore that would fit it? And that simply putting it in an adapter would have fixed it? I am quite sure that given the right size, a sim card will just work in any unlocked phone. New sim cards should still adhere to basic specifications though they may have some new features other than simply being smaller. As Jonathan said, most likely this employee just doesn't know what he/she is talking about.

| improve this answer | |
  • Most SIM cards are sold with all 3 standard formats in the same package. – JonathanReez Jul 22 '17 at 8:05
  • That's not an answer. – fkraiem Jul 22 '17 at 8:05

If your iPhone is newer than iPhone 5 (nano-sim), most (probably all) major 3 Korean carriers (SKT, KT, LG U+) should have SIM available. Can't confirm if you're on micro-sim.

| improve this answer | |
  • he says quite clearly it's an iPone 4 with a micro sim :) – jwenting Jul 26 '17 at 5:30
  • 1
    @jwenting "I'll be going to Japan and Korea this September, and I've got a more recent iPhone as well" (emphasis mine). – revi Jul 26 '17 at 5:47

Apart from maybe having to cut down a larger sim to micro sim size, any sim should work in the phone BUT you might not be able to use all the network services.

E.g. your phone only has 2g data (probably), so their 4g network which you're paying for will be downgraded for you to 2g performance.

Usually those guys telling you they can't sell you what you want is an attempt to sell you something else, something like a late model phone...

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.