Switching iPhone Sim cards: Standard vs. MicroSim

A friend of mine is getting a new iPhone 4 by using his wife’s upgrade eligibility. The plan? Take the Sim cards from his current 3GS and the new handset, switch ‘em and give the wife the older phone. The strategy would’ve worked seamlessly – except for that pesky MicroSim card tray in the new handset.

I was going to give him grief for being so greedy and taking his wife’s upgrade, but it turns out, she wants his old 3GS. (With its rounded back, she prefers the way it fits in her jeans and purse.) Well okay, if she’s fine with it, who am I to argue? Then I asked him if he noticed that part of the WWDC keynote – or the thousands of blog posts that followed – stating that the new phone would have one of those smaller MicroSims, just like the iPad. (The reason, says Jobs, is to save some room inside the device.)

Indeed he did notice that. And, it turns out, he has a plan.


Fast facts:

Sim cards are what allow a phone to identify itself and communicate with a carrier’s network. In other cases, it can also store stuff like contacts and other data. But since iPhones sync all that via either iTunes or over the air, our Sim cards don’t actually contain this info. (So in other words, without a Sim, our iPhones are basically iPod Touches.)

Standard Sims and MicroSims both have chips that are electronically the same, as confirmed by the GSM association. So the only difference is the extra plastic casing the chip’s embedded on.



So the challenge, as he saw it, was figuring out how to get his standard Sim from the 3GS to fit in the 4’s MicroSim card tray. And then, how to up-size the the 4’s MicroSim (his wife’s) to fit in the 3GS standard tray. (EDIT: My friend is using his iPhone on T-mobile. If he was on an AT&T Family Plan with his wife, this swap would’ve been far simpler. In fact, the carrier or Apple itself could take care of it for him. For more on this, see below.)

With the arrival of the iPad 3G, plenty of resources cropped up for dealing with the Sim/MicroSim size differential. (A lot of people wanted to use their Sims interchangeably between the iPhone and iPad to share the data, instead of getting two independent plans.) And thanks to crafty Sim hackers and swift-moving entrepreneurs, there are a lot of ways to approach the size dilemma.

A little Googling reveals that the previous iPhone models’ Sims are trimmable to fit a MicroSim card tray without loss of function – at least in the iPad 3G. Obviously, no one’s tried this with an actual iPhone 4, since they’re not out yet. But the early predictions look good. MicroSims have already proven to work in older model iPhones (see video at bottom), with the addition of an adaptor of some sort to up-size the card. (And if you presume that AT&T doesn’t sanction this, you’d be right. So proceed at your own risk, if you decide to give any of these hacks a go.)


That said, here are some resources* we found:

There are a few different ways to cut down a standard-size Sim card. For the brave, but unsure, there’s SIMCut, a stick-on guide for sale for almost $10 USD (shipped from Europe). It’s a transparent sticker foil that shows the cut lines when you adhere it right to your Sim.

Then for the inordinately brave, there’s always the freehand approach using a cleaver. (Yikes!)


To be fair, the cleaver in this tutorial is just used to score the cut lines, in this case, on a Vodafone Sim card. You’d actually use scissors to trim it down. Of course, if you have access to a laser cutter, you might be interested in Brandon Shigeta’s techtastic hack instead.

But most of us will probably use Xacto knives or scissors, and there are several online tutorials using those. Here’s another one from TouchUserGuide.


There are also specialized hand tools due to come out next month. These proclaim they will precision-cut your standard Sim card down into a neat little MicroSim size. (I have to hand it to the Europeans – if it’s one thing they know, it’s definitely Sim cards.)

One called Cut My SIM also includes an adapter that lets you reverse-fit your MicroSim card into a standard size Sim. The site has started taking pre-orders for shipping to locations worldwide, including the UK, Canada, and the U.S. (US residents, there’s also a introductory special for $25 USD if you order in June.)

RebelSimCard also has a cutting tool for pre-order, but it’s not apparent if it includes the adapter. Looks pretty similar to Cut My Sim, but it’s selling for less, at $14.78 USD. (We’re not familiar with RebelSimCard, but if you are, please weigh in on your impressions below.)


If all you need is help with is up-sizing a MicroSim, then you’re in luck! Some sites sell the adapters alone (often for less than $10 USD) – like MicroSim-Shop or MicroSim2Sim.


In the case of MicroSim2Sim, it offers a cheap price (at $6.50 USD) for the adapter and includes a handy sizing sticker that’s similar to the SIMCut foil sticker mentioned earlier. You just paste it onto a standard sized card, and it shows you where to cut.

But there’s also a DIY approach to adding more surface area. If you’re determined not to spend a cent on these hacks, here’s one way you could go: This guy did it using a cut-out credit card.

For the full instructions on how to do it, click here. And to see evidence of this hack’s success, check out the vid below showing it working in an iPhone 3G.


A big thanks to my friend (who wishes to remain nameless) for letting me share his story (and some of his resources).

So what do you think? Will anyone be trying any Sim hacks? Or know of any options or resources that’s missing? Add to the list by commenting below. And if anyone’s had any firsthand experience with this – good or bad – be sure to weigh in.



*Today’s iPhone offers this for informational purposes, with no guarantees or representations as to its completeness or accuracy. If you choose to try any of these products or hacks, you do so at your own risk and assume full responsibility for the outcome. Neither AT&T nor Apple condone the unauthorized use of Sim or MicroSim cards in any iPhone models.



NOTE: Readers Breadbox and billnewl point out a pretty obvious omission here – the most elegant solution to this dilemma is to just hit up AT&T. Breadbox notes that the carrier will let people on a Family Plan use each other’s upgrades, while billnewl suggests purchasing a new set of Sim cards. So simple, so brilliant. Thanks, guys.

As for my friend, I’m not sure if he’s currently using AT&T or Tmo, so if it’s the former, it would be quite the “Duh!” answer. But if it’s the latter one, then he – and others like him – might be relegated to chopping up that card. And that may be okay. If he does it once, he’ll know how to do it no matter his GSM carrier in the future.


UPDATE: Looks like there’s also a Micro Sim Cutter available for $30. It may be overkill, unless you’re planning to trim down a load of sim cards. Click here to check it out.

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  • Breadbox

    If he’s in a family plan with his wife then he can just use hers. AT&T did it to my girlfriends plan and her moms. Her mons was up and my girlfriend wanted the new iPhone so my girlfriend used her mons eligability. So if they’re on the same plan the n AT&T will do it. You just hav to go in and tell the m to do it.

    • Bradley

      Guys, I heard there is a thing called micro sim adapter. AFAIK these guys sell it here: gomicrosim.com .What do you think, is it worth buying one? They say it allows me to use my micro sim card from Ipad in my old Iphone 3g, thus saving bucks on the data plan.

      • Adriana Lee

        Hey, Bradley. I actually bought an adaptor from MicroSim2Sim, as mentioned above. Using this, I can interchangeably fit the same sim card between my iPhone 4, iPhone 3GS or whatever other GSM handsets I may be trying out. Right now, I’m using it in an HTC Aria, which I’m reviewing for PhoneDog. (We may do a little write-up here on TiP as well, so if you’re interested, stay tuned.)

        I’m dubious about using a MicroSim from the iPad in an iPhone 3G, only because there’s no calling feature on the iPad plan. If you were planning to just use the data connection only, though, it might work.

        At less than $10, these adaptors are so cheap, there’s probably very little reason not to try it out. I’d do it for you, but my iPad is Wifi only :-(

        If you give this a shot, let us know how it pans out!

  • Adriana Lee

    Hey, that’s good advice! And way easier than hacking into a Sim card. Truth is, I don’t know if they’re on a family plan. In fact, he might even be on Tmo, since I’ve heard him wax poetic about jailbreaking and unlocking. In any case, I’ll pass this on and let him know!

  • billnewl

    If they are just switching phones, why doesn’t he just go to AT&T and buy two new sim cards. It will cost him 20 maybe 30 dollars.

  • Adriana Lee

    That would certainly be an elegant solution. But again, I don’t know if he’s actually on AT&T. And I think he – like others I know – would prefer the DIY route anyway, since the instructions or tools should work on any Sim or MicroSim, even beyond this one situation.

    But thanks for sharing. It’s still good info for people to know.

  • Neerav

    We’re with AT&T on a family plan.. my dads eligible but im not and i want the new iphone.. how do I use his upgrade?

    • Adriana Lee

      Hey, Neerav. I haven’t done this myself, but based on what Breadbox is saying above, it seems like you can just go to the store, tell the rep what you want to do (with your Dad in tow – he’ll need to give his permission), and the guy might be able to handle it for you.

      This might be tough right now, with AT&T holding off on any new iPhone pre-orders at the moment, but when they resume, this could be a good way to go. (And if it’s wrong, the worst that will happen is the rep will say no. No harm, no foul.)

      I’ll try to get a hold of a friend at AT&T, and see if he can confirm this for ya.

      • Neerav

        Thanks so much!

  • Mark Crosby

    I’m upgrading using my wife’s eligibility as well. My understanding was that (at least on phones purchased from an Apple store) the phone has a “blank” SIM card pre-installed and that your phone number is coded to the SIM when you connect it to iTunes the first time to set it up and sync your contacts, apps, and media, etc.

    I may be way off base here, but that is my recollection.


    • Neerav

      I read something about how when ordered the phone arrives with a blank sim, but wasn’t sure how that works in terms of activating it.

      I’ll see if I can find out. Let me know if you do!

      • Neerav

        I found this on http://guides.macrumors.com/iPhone_Upgrade_Guide

        3. UPGRADE SWAP – Can I use someone else’s upgrade? Yes, this is called an “upgrade swap”. If you perform this in an AT&T store, they will handle it all for you. Apple should be able to as well, but they will need to contact AT&T during the process.

        If you prefer to order online, place your order for the phone using the line(s) that has an available upgrade. If this line currently has no data plan, you may need to add a data plan (just choose the cheapest as you will be removing it later.) Once the phone(s) arrive contact AT&T to let them know that you will be activating the phone(s) on another line (performing an “upgrade swap”). (If you had to add a data plan, have them remove it at this time as well.) Once AT&T has reassociated the SIM with the correct line, connect the phone to iTunes to complete the activation. DONE!

        This process does not affect your unlimited data plan.

        4. What happens to the contract when performing an Upgrade Swap? The contract on the line that had the available upgrade will be renewed for 2 years. The line that the phone was transferred too will not be affected.

        • Adriana Lee

          Hey, guys. This is an awesome conversation.

          So I spoke to my friend, a rep at AT&T, and he confirms that the MacRumors info is correct: You can do a “role reversal” to take another user’s upgrade (if you’re in the Family Plan). But you have to do it in-store at AT&T or Apple; you can’t do it yourself via iTunes. And yes, the contract of the original line with the upgrade eligibility will get renewed for 2 years.

          FYI: The Sim card in the iPhone is not blank, it’s already pre-programmed, but syncing it to iTunes is what will activate it.

          This doesn’t help my friend, but hopefully this discussion will help some of you other “swappers” out there!

  • Mark Crosby

    Nice work Adriana and Neerav! Guess I’ll be calling AT&T customer service on what’s going to be their busiest day of the year (god help me) on the 3GS during my drive home to activate my new baby

  • jana

    I am getting my first iPhone through an eligibility swap onthe family plan. Can I cut my current ATT sim card down to fit the iPhone 4? Or does the iphone use a special SIM?

  • Brendan

    This IS a great conversation. And I’d like to add that I spoke to ATT today and you can make an upgrade swap even in they aren’t in your Family Plan. I was told you just need to call once the Iphone 4 has been ordered and received by the person with eligible upgrade and they will transfer it to the account of your wishing. I was informed of this after explaining that my brother ordered one and was giving it to me as a gift, and that we are not in a family plan.

    • Adriana Lee

      Wow, Brendan. Neither of the two reps I spoke to even mentioned this. Nice work, man!

      Can anyone else corroborate this? (As for me, I’ll also go back and check. Might take a bit, considering they’re swamped this week, but I’ll give it a go.)

      • tom

        i did this as well. i actually added a line, swapped the iphone over to my existing line (ineligible for an upgrade) and then gave the extra line my old phone.

  • Shay

    I upgraded under a family member’s line since I am not eligible until mid July. I don’t know why, but I mis-read MicroSIM for MicroSD (I guess I had wishful thinking). When I realized that the simple sim card-switch wouldn’t work, I called AT&T to see if I can do the “role reversal”. The lady I spoke with told me that only the line that I upgraded will work with the SIM card and that I can NOT simply buy a new SIM and switch it because they are currently not available for sale. She also wouldn’t switch my upgrade then and there.

    I called Apple to cancel my order but I was on hold for too long and saw this article. I won’t cancel it. I’ll just wait until it arrives and go into a AT&T store and speak with someone. Hopefully it doesn’t turn into me having to go to an Apple Store and returning the phone. ( I would have rather cancel the order before even getting it).

    Fingers crossed!

  • cmck

    Awesome thread, guys! I have a question that no one has asked yet. I ordered an iphone 4 at full price because I wasn’t eligible for the upgrade. I’ll be adding a line to my family plan and planned on canceling my order and giving my 3GS to the new line and me taking the iphone 4. Unfortunately (but also exciting), my iphone 4 has shipped earlier than expected so we haven’t added the new line yet.

    All that to say… I plan on returning my iphone 4 and using the one purchased for the new line. My question is, if I want to return my already shipped iphone (once it arrives), does anyone know if I can use that phone for the new line (walking it into ATT, not returning it to Apple) and get a refund for the difference between me paying full price and the new line’s eligibility price?

    Kind of a tricky situation so I’m seeking your help before calling ATT directly. Thank you!

    • Adriana Lee

      Not sure if AT&T can do anything about a transaction you placed elsewhere. But if all else fails, it’s worth a shot.

      You may want to start by calling Apple first. (Since you bought it there to begin with, they’d be the most likely one to be able to help.) Not sure if they can do it over the phone or if you need bring the device to a store, though. Either way, at least that would beat shipping it back and waiting weeks for a new one to arrive.

  • Ben

    Don’t waste your time or effort. I found one from an American retailer for only $6, here: http://www.luxmo.com/p-1501-luxmo-micro-sim-adapter-with-cutting-label.aspx (Cheaper than all those listed in the article.)

    • Adriana Lee

      Good job on that. Looks like the adapter is regularly $9, but there’s a $6 intro price. I paid 5.99 Euros, which works out to about $7.59. So yeah, I paid about a buck and a half more.

      Nice tip, Ben. Thanks for letting everyone know.

  • By the way, for those who want to be able to interchange SIM and MIcroSIM devices there is a smart gadget – a MicroSIM (3FF) adapter. One is available at approx. 5.79$/unit on the web.

    For instance, check http://www.buymicrosimadapter.com

  • The mico-SIM adapter (converter) allows you to use newest Micro-SIM (3ff, mini-UICC) cards both in iPad or iPhone 4 and your normal mobile phone with no additional equipment.http://www.szfeifan.com

  • Amy

    this article seriously saved my life…my iphone 4’s battery died and I had to send it in…being left without a phone was not an option so i wanted to use my old iphone 2g…the simple DIY instructions totally worked and saved me from being without a phone! thanks!

  • Greg

    I created the little adapter for a microsim so that I would be able to use my iPhone’s at&t service on a different att older Gophone. The first time I put the sim card in the older phone, it worked. The second time and on it has not. It won’t recognize the sim card, even though they are both at&t phones. Does anyone know why this might be happening, and how I could get it to work again?
    Thanks, G

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  • captainjaneway

    If you bring your samsung 111 to Ecuador,Do they have a sim card available that will fit?