The Rise And (Eventual) Fall Of The SIM Card

There are few devices that better exemplify the breakneck pace of modern technical advancement than the mobile phone. In the span of just a decade, we went from flip phones and polyphonic ringtones to full-fledged mobile computers with quad-core processors and gigabytes of memory.

While rapid advancements in computational power are of course nothing new, the evolution of mobile devices is something altogether different. The Razr V3 of 2003 and the Nexus 5 of 2013 are so vastly different that it’s hard to reconcile the fact they were (at least ostensibly) designed to serve the same purpose — with everything from their basic physical layout to the way the user interacts with them having undergone dramatic changes in the intervening years. Even the network technology they use to facilitate voice and data communication are different.

Two phones, a decade apart.

Yet, there’s at least one component they share: the lowly SIM card. In fact, if you don’t mind trimming a bit of unnecessary plastic away, you could pull the SIM out of the Razr and slap it into the Nexus 5 without a problem. It doesn’t matter that the latter phone wasn’t even a twinkling in Google’s eye when the card was made, the nature of the SIM card means compatibility is a given.

Indeed there’s every reason to believe that very same card, now 20 years old, could be installed in any number of phones on the market today. Although, once again, some minor surgery would be required to pare it down to size.

Such is the beauty of the SIM, or Subscriber Identity Module. It allows you to easily transfer your cellular service from one phone to another, with little regard to the age or manufacturer of the device, and generally without even having to inform your carrier of the swap. It’s a simple concept that has served us well for almost as long as cellular telephones have existed, and separates the phone from the phone contract.

So naturally, there’s mounting pressure in the industry to screw it up.

Home is Where the SIM Is

With landline telephones, it was “easy” to figure out if the bill was paid. The carrier knew where each subscriber lived, and they knew where the phones were installed. The homeowner either paid the bill and got service, or they were cut off. Even when the earliest mobile phones started hitting the market, their large size and high cost meant keeping track of who owned them wasn’t too difficult.

But as mobile phones became smaller, cheaper, and more widespread, it was clear some method of authentication would be required to prove the user had an active account. Since the physical location of the phone could no longer be used to determine who owned it and what number it should get, it would be necessary to give each mobile phone its own unique ID number. Further, since it was inevitable that the subscriber would eventually get a new mobile phone, it made sense to tie their information to some removable storage device so it could be moved between devices.

Thus, the Subscriber Identity Module was born. First introduced in 1991, the SIM card was actually envisioned as a way to carry the subscriber’s entire “digital life” between devices. It featured enough storage capacity to hold the user’s contact list and messages, which would be carried over to whatever new device the SIM was installed in. This concept has been all but abandoned today, as not only is the SIM’s storage capacity (less than 0.5 MB) laughable by modern standards, but we now have the cloud to allow seamless syncing between devices.

Modern SIMs are used almost exclusively to hold data necessary for network authentication. This consists primarily of the Integrated Circuit Card Identifier (ICCID), which is the SIM’s own serial number, and the subscriber’s account number, officially known as the International Mobile Subscriber Identity (IMSI). The IMSI includes identifying codes for which country and network the card is to be used on, as well as the subscriber’s phone number. In addition, the SIM contains a unique 128-bit authentication key that is checked against the carrier’s database when the device attempts to join the network. Naturally this is all an oversimplification — [LaForge] gave a fantastic talk on the nuts and bolts of SIM cards at 36C3 if you’ve got an hour to spare.

Nano-SIM with Micro and Mini adapters.

The first generation SIM cards were the same dimensions of a credit card, and generally were installed in car phones and other large portable telephones. By the time 2G cellular technology was mainstream, phones were much smaller and were using what at the time was called a Mini-SIM. For many years this second form was the defacto form of SIM, to the point that most people think of it as the original. But ever-shrinking smartphones necessitated something even smaller. This lead to the adoption of the Micro-SIM in 2010, followed by the Nano-SIM in 2012.

Interestingly the size of the SIM card was dictated by ISO/IEC 7810, an international standard for the size and shape of identification cards, rather than the internal electronics. Each version of the SIM has utilized essentially the same active components, just mounted to smaller and smaller PVC cards. This allows the larger cards to be cut down to fit devices which use the smaller forms, while the smaller versions can be used in older devices by way of an adapter.

Understanding the design of the SIM card and its various forms, it’s clear that the Nano-SIM is the end of the road. There’s only enough of the PVC card material left to orient the chip in the holder — any less, and you’d have to cut the chip itself, which could potentially break decades of backwards compatibility.

So how do you make the a SIM even smaller? Easy. You get rid of it.

Breaking the Nano Barrier

More and more phones today support what’s known as an Embedded-SIM (eSIM), which as the name implies, is built directly into the device. In practice, there’s still a dedicated flash chip that hold’s the subscriber’s information, the user just can’t get to it. But for some devices, such as a smartwatch, even an eSIM might be too large. In that case, there’s growing interest in Integrated-SIM (iSIM). With iSIM, the physical component is removed entirely — instead a sort of virtual SIM is integrated directly into the device’s System-On-Chip.

While most phones still offer Nano-SIM compatibility in addition to eSIM, the clock is ticking. Apple has already done away with physical SIM support as of the iPhone 14, and if history is any indicator, other manufacturers will soon follow. As of right now iSIM is being marketed towards wearables and IoT devices, but it’s not hard to predict that phone manufacturers will eventually be interested in the technology.

Who’s SIM is it Anyway?

With no physical SIM to remove, accessing and changing the data on the eSIM/iSIM must be done through the device’s own software. Naturally this means that not only will it require the latest-and-greatest version of your mobile operating system of choice, but that it’s possible for your device manufacturer or even carrier to control your access to it. Just as some carriers disable the option to unlock the bootloader on Google’s Pixel phones, one can imagine a future in which carriers will require you go through them every time you move your eSIM to another device.

In fact, there’s some scenarios in which you’ll almost certainly have to contact your carrier. Bust up your current phone bad enough that you can’t perform the self-serve eSIM swap? You’ll need to get the carrier to do it remotely. Want to switch eSIM between iPhone and Android? You guessed it, call the carrier and have them do it remotely.

To be fair, there are some potential security benefits to eSIM/iSIM. For one thing, you don’t have to worry about somebody stealing the SIM from your phone or replacing it with another one while you aren’t looking, because its not a physical object. Of course, that’s right now — who is to say a piece of malware couldn’t be crafted down the line to extract the subscriber information from the hardware?

In any event, it seems inevitable that the consumer won’t have much say in the matter going forward. Sure you can avoid buying a phone without a SIM card slot in 2023, 2024, and probably even 2025. But just as fewer and fewer phones each year still include a headphone jack, your options will eventually become limited. The day is coming when you’ll have to bid your trusty SIM card goodbye, and that’s a shame.

SIM diagram based on “GSM SIM Card Evolution” by Cvdr, and released under the CC BY-SA 3.0.

107 thoughts on “The Rise And (Eventual) Fall Of The SIM Card

  1. … and you left out the original SIM card in ~credit card format in the article’s main image. :-(

    > In fact, if you don’t mind trimming a bit of unnecessary plastic away, you could pull the SIM out of the Razr and slap it into the Nexus 5 without a problem.

    That is in fact just wrong. If your SIM card is as old as the Razr it’s electrical contacts might be too big to “just” cut away at the plastic and get it down to nano size.
    Had to cut it down previously from mini to micro which mostly worked but cutting it down to nano and it stopped working entirely. My guess is that one connection between chip and contact broke during cutting.

    1. That’s the whole point of the adapter shown in the post, the electrical contacts in the phone have remained essentially unchanged since the 2G rollout, only the outside shape of the card changed.

      I’ve had the same SIM now for at least 15 years, from before I had a smartphone. I’ve had to trim it down like the article says, but I could still go back and put it in any of my old phones if I used the adapter.

      Obviously anything older than 4G isn’t likely to actually work anymore, but that’s not the fault of the SIM.

      1. (two larger vs. two smaller)
        Notice the outer ring? Where some contacts are just floating but others are connected to the “normal” pads?
        Cutting down those can/could even lead to short circuits when the slot’s shell is made from metal.

        To quote myself:
        > (the SIM card’s) electrical contacts might be too big to “just” cut away at the plastic and get it down to nano size.

        No adapter will help there.
        Adapters help you to fit small SIMs into larger slots but not the other way around.

        TLDR: Cutting away just plastic is not always enough.

        1. You’re talking about weirdo edge cases that few are going to run into. Razr is mini SIM, Nexus is micro SIM. That’s like the most common trim in the world. Even in your first comment, you said you’ve done it yourself, so don’t understand why its so hard for you to believe.

          1. That might be a problem of my sample size “one”.
            But from the linked Wikipedia images I assume(d) that the default/in-spec mini-version’s contacts are too big to get it to nano size without cutting any contacts.

            Which lead to the failure of my SIM after the second trimming I’m reasonably sure.

        2. This is primarily what prevents me from replacing the phone I have now… my present phone takes a mini-SIM… and the card I have was last replaced in 2009 (moving from 2G to 3G) when mini-SIMs were the standard. The SIM I had before that was also a mini-SIM format.

          I did once use a phone that took a full-size SIM: Motorola MicroTAC… and I recall using the original SIM to figure out how to cut up an old plastic ID card so I could slot my mini-SIM into it and use it in the old brick when the Ericsson A1018S I was using at the time died.

          I’m not game to go cutting up my only means of accessing the cellular network to make it fit in a newer phone until the phone I’m using now literally stops working and I’m left with no other choice.

    2. I’ve used a SIM card punch before and they do work. It’s possible they don’t work in every situation but all the card form factor products I’ve dealt with (DirecTV access card, SmartCard, etc) are no different in size as the die for a glop-top chip used in toys for the last 30 years. The only time you’d have electrically important bits outside of the chip area of the I/O pads would be for a radio and antenna, which a SIM card does not contain. I would be surprised if a card from the 1990’s deviated from what I’ve seen of similar form factors over the years. And I’m confident a card from the early 2000’s has the same chip foot print as micro and nano SIMs today.

    3. yep, I’ve trimmed some plain SIM to micro sim before, and you definitely have to cut through the top contact, but normally the chip is not located there and it works just fine

    4. I have a card that predated The Razr… It came with a Nokia 5190 near the turn of the millennium. I used the 5190 until I couldn’t get a replacement battery any more, wore out like 5. Then /upgraded/ to a Razr V3, then used that for 5 years maybe, then it went in a LG Android nougat phone, then it was trimmed to fit a G4, then just last year I quit that provider and that SIMM. So some 22 years I think that one lasted.

  2. Some extra notes:
    The smallest version is also thinner, so you’d also need some sandpaper.

    An advantage of the separate SIM card is that it’s separate :)
    Suppose you’re on a trip, accidentally drop your phone in the water or a truck drives over it and it dies. With a separate SIM card, you have a pretty good chance you can just put in some random phone and it works again. Even if you have backups of all your contacts, it still may be difficult to reach them when you’re on a trip.

    You can also always rely on the fruit brand to be a fore runner when it comes to further limiting user freedom. I’ll bet they’ll start charging again for ringtones on your phone if there was any chance the’d get away with it too.

    1. audacity software work some magic maybe a Dec** to use what you already owned {not that i ever used it, wait, what, where am i, who am i}, then finished product place in ringtone folder. yep if you traveled non state side you could just buy a sim at the airport and use a local plan for cheaper than what your state side carrier would charge you for an international service usage charge. Remember whole disposable phones before the powers that be freaked out they couldn’t know who was who or every-step you were making, talk about helicopter governing. Then the old cellphone light up antenna display cases that just were basically low powered cell signal blockers if you got near them at the store. sorry I went on a tangential rant , lol .

    2. Yes, good point. I’d still consider that covered under “minor surgery”, but for sake of clarity I probably should have specified that the Nano is smaller in all three dimensions.

      I had to sand my own my Micro to a Nano (probably when I got the Nexus 5X in 2015), and while a hassle, at least it was still something I could do on my own without having to ask the carrier’s permission.

    3. yes if you went non state side you could buy sims or even disposable phones rather than pay your carrier a high fee to use your current service overseas. Ringtones were handled with Audacity and DeC**. Ptt was an amazing thing. Also when demonstrating cell service in the store you had to make sure to turn off or be a good distance from the display case that ran the light up antenna or batteries display case, because the display case acted like a jammer. lol I went on somewhat of a tangent

    4. This is incorrect, at least in Europe – I’m holding an iPhone 14 pro, and it’s got a SIM card slot on the side. iPhones support eSIM and regular sim, I believe so you can pick up a cheap PAYG if you’re roaming abroad.

        1. The US has a bizarre mobile phone ecosystem compared to most of the world. Weird stuff like carriers rebranding phones, incompatible models (not just the CDMA malarky, but different GSM models!), locked as standard with no way to unlock out of contract, random un-removable software preinstalled, exorbitant fees, randomly variable coverage with no cross-carrier-roaming, etc.

          1. You can say that again! The Free Market in the US is a continually changing soup of incompatible systems and carrier locked phones.

            I dream of a country where the infrastructure is shared (one set of antennas per cell base station) among multiple carriers, and any phone can work on any carrier.

      1. The SIM card is a great democratizing and competition encouraging system, so it’s quite natural for US carriers to want to get rid of them. Look at all the trouble they went to for these stupid subsidy locks, and what an artificial nightmare and force for tremendous e-waste that is. For anybody else in the world, it’s a trivial matter to walk in to a 7-11 and buy any number of different, shockingly affordable SIM cards. Except that when Americans travel, they had better make sure their stupid phones are “unlocked” and don’t count on the promises of the carrier for timely help with that either.

        SIM cards forever!

    1. Interestingly a SIM card is indeed a separate processor, and it was discovered that it on its own can and does make calls completely outside the phone’s operating system.
      Someone discovered it calls and relays information about itself and what phone it was in previously and such, and does so without the user ever realizing.
      So it’s not as innocent as it seems, and less private too, and not that much in your control actually.

  3. I wish the phone companies still kept the sim card around. Very useful if you are travelling. The local Cellphone carriers are way cheaper than extending my AT&T plan for international travel. Easy to temporarily borrow my friend’s or family’s sim card, put it in my phone and use it right away rather than messing with eSIM transfer.

    1. You can just buy an eSim online and add it to your phone before you even travel then just select it in your phone’s settings when you land. Cheaper as well. One less thing to be worried about when you travel. A much better experience IMHO.

      1. Buying a simcard is a nightmare in India for example, if you are not a citizen. So when I travel, I borrow simcard from family to use it temporarily. Esim will make this so much harder or even impossible.

  4. Sim-Cards also come with three different operating voltages. 5 V, 3 V and 1.8 V. The operating voltage of the majority of SIM cards launched before 1998 was 5 V. SIM cards produced subsequently are compatible with 3 V and 5 V.
    So the (very) old cards might not work in newer devices, while the new cards might work in the old devices.

    1. Today’s SIM cards only need to support two of those voltages. Mostly they do 3.3V and 1.8V.
      I know this because I once tried to use a new SIM card on an old 2G portable phone. Turns out: it pumped 5V into that card that could only handle 3.3V.

      It was the Motorola International 1000. (You can even still buy batteries for that thing, lol) It actually has two revisions of the “phone”-part. One that uses 5V and one that uses 3.3V. I’ve managed to obtain a 3.3V model later on and successfully used a T Mobile SIM Card with it.

  5. I have been using PDAs from around 2003 and Treo 680 from like 2007? So, I have not been amused by first apple and android smarthpone that much. For, me it was just a nice evolution step. But, reading the intro of this article, it had to be a great jump for regular people.

    1. Whaaaat?!? You’re comparing PalmOS to iOS and saying iOS wasn’t that impressive? Windows CE, PalmOS, and Maemo were all the rage when the iPhone came out and pretty much dead inside a year.

      PalmOS never felt like a true computing device, it always felt like one of those Franklin pocket organizers or translators. Even when you could install apps on them, they were all pretty lack luster.

      I remember sitting with my Nokia phone balanced on my knee trying to connect my Sony CLIÉ to it via IR to browse some WAP pages on the internet because it didn’t have enough RAM to load regular web pages.

      iOS made everything else on the market a joke when it came out. Android was pretty bad compared to iOS and it was light years ahead of WinCE and Maemo.

      1. > iOS made everything else on the market a joke when it came out.

        Yea, sure. First version couldn’t even do copy-paste :-D

        iPhone 3 refused to send photos over bluetooth that ANY smart device could do at the time, but drink your coolaid ;-)

        1. I didn’t know you could, nor have I ever tried to send a photo over Bluetooth. If that obscure feature is your baseline for how much better PalmOS was then I guess you got me…

          1. No. It isn’t a baseline.
            But… simple scenario – photo is taken on an idevice, you ask for it, and both sides find out that the only thing that iphone could share over bluetooth were contacts. The year was 2009? By that point ANY PDA/computer/etc could send files/contacts/whatever over bluetooth for 5 years already.
            Progress, indeed.
            Technologically speaking, iPhone was a huge step back. But it sold ‘experience’ and ‘ecosystem’, so users flocked.

            You choose your’s I choose mine. Palm had much more decent PDA capabilities. Software wasn’t as ‘polished’ as iPhone, but it worked. And you could actually develop it, without getting approval from ‘big daddy’.

            PS. you conveniently didn’t do anything with the first argument ;-)

          2. wait a sec sending photos over bluetooth is obscure? how else do you transfer/share files from your mobile device… whatsapp? granted cable is faster for larger files if going to a laptop but then browsing the phone’s file system from that is not a convenient experience

          3. It is 2023 and iPhones still require external app for file transfer (other than photos and videos). My iPhone is my first and last Apple device – despite it’s advantages it is first smart device that requires me to google how to do basic tasks (just to find some times they are impossible).

      2. Yeah, PalmOS. Where you could get a free dev kit and people wrote hundreds of free and commercial apps for it while iPhone was still not sure why anyone would do anything except for a web-based “app” on their device. And PalmOS was heavily inspired by Apple Newton in both form factor and the basic structure of its operating system, right down to having resource forks.

        Palm briefly had the better devices but 3Com wasn’t investing into improving how people used it, only in the raw system specs of new handhelds. Handspring was on a good track with Visor and Treo. With some early success at a fairly open smartphone that could handle voice and internet and let you load whatever app you wanted into it. But again, the hardware treadmill that was killing 3Com/Palm ended up bringing Handspring down.

        Apple wins because they had a vision and expanded on it. Even if their initial concepts were weak and derivative. Selling an experience instead of selling hardware specs is the smart play in consumer devices. There are way more people that want to make a phone call than want to know how much RAM and MHz they are buying.

          1. Nope. I did write my own apps for my Tungsten T (so a generation too early to get phone support).

            I went for Nokia N900 as first smartphone. And also did write my own applications.

            Then Samsung S-series phones when Nokia peed on all N900 users.

      3. It only took 3 years for Android phones to pass up iPhone to the #1 spot in total number of units sold. That’s when Steve Jobs did his anti-Android rant. IIRC it’s also when Apple finally got around to increasing the iPhone display resolution to try catching up to the Android phones all getting bigger displays. Then there was his mocking of smaller Android tablets with his comment about how they should come with sandpaper for people to make their fingertips smaller – when he was insisting Apple wouldn’t make a mini iPad (while conveniently ignoring the existence of Apple’s tiny iPhone and iPod Touch).

      4. Considering that PalmOS was ~15 years older and absolutely tiny by comparison, it was astonishing capable and did a decent job at rivaling that behemoth that iOS was. IMHO.

      5. Maemo didn’t die because it wasn’t good enough. But Nokia loved Microsoft too much and even left it to hobbyists to implement SMS support.

        But the Nokia N900 was a dream in how well it did run multiple programs with true multitasking.

  6. Older analog cellphones had the predecessor of the eSIM. Basically the phone number was encoded into a EEPROM, and when a new carphone or cellphone had to be leased, the data was burnt on the phone by an authorized dealer. You leased the phone by The Phone Company, so interoperability problems weren’t a thing. When priced started to fall it was possible to buy an analog cellphone but only The Phone Company had an exclusive. With GSM, that for some time coexisted, there was The Phone Company and the Other company, and having a SIM meant that people could switch operators easily if they had a bought phone. Operators weren’t and still aren’t happy of this.

    1. That reminds me of the classic telephone agencies, which allowed citizens to borrow/rent a telephone for the landline.

      Or here in Germany, we used to have the DBT-03 modem for the ~1980s BTX online service (rented, not sold).
      It was a little blackbox (gray box, rather) with an early, integrated microcontroller and a pre-programmed EPROM containing the hard-coded “Teilnehmerkennung” (user ID). If a pin on its serial port was toggled, it started to auto dial to the national wide available telephone number of the service – via pulse dial, of course -, transmitting the ID for login and let DTE do the rest. (speaking under correction, it’s been a while)

      1. I can still hear my late dad telling us that we need to rent additional phones because Bell could tell how many phones you had by the impedance on the line.

        We more or less ignored him and installed cheap phones on every extension.
        Dad was a rules crazy German.
        Check that, he was beyond rules crazy by American standards, but relaxed and slackful by German ones.

  7. So, we are going back to TDMA / CDMA days, when you had to go to a carrier shop to change your number to another phone. Yeah, that´s what apple calls progress….

    1. This is progress, now SIM cards can just be downloaded from an app.

      Every instance of “Call your carrier!” in this article is only half truth, you CAN call your carrier to do it but you can also just sign into your carrier app and download it, or view the QR code/text code online on your carrier’s website and load it without the app entirely. Google is working on a way to make it transferable between devices as well, so it becomes part of your standard data transfer process when getting a new phone.

      You might need to call the carrier in some edge cases, but this was also the case with SIM cards – activations often just go wrong and there’s nothing you can fix user-side.

  8. My carrier sent me a SIM card that is punched for the three sizes. There’s a gap in the plastic that provides a friction fit between the different sizes. You can snap the card out to reduce the size, so no trimming needed.

    1. I meant to add.. if you only want a micro, and not a nano, this form of card with the friction fit is a PITA. The card fell apart and I had to snap the two parts back together to keep the card as a micro rather than a nano.

      1. I had this exact same problem, so the ‘obvious’ solution was to spend most of a day writing some OpenSCAD code to generate an adaptor between any two sizes of SIM. (Even credit-card size, because I wanted to be through).
        I quite enjoyed myself pouring through the official specs to make sure everything was correct (even the size of the radius on the corners).
        I think I only used it to 3D print one adaptor, but I still have it somewhere :)

  9. Consumers shouldn’t accept this. Phones are already too thin, so space is just a lame excuse to drop the headphone jack or sim card holder. I don’t want a portless phone.

    1. The phone companies very very very much want to make a portless phone to reduce costs. And I agree with them.

      You can’t break connectors that aren’t there. You can’t plug stuff in the wrong way. You can’t get water or cat fuzz into holes that are not there. You don’t have to waste time hunting down a cable that you don’t need.

      Our Devices are supposed to save labor, not create gratuitous busy work.

      1. You break the connector (for Apple at least) then it’s more $$$ to them to fix it. Nothing to break, no service income.

        There’s still hope, after turning macbooks into USB-C powerbanks with keyboard & screen for a few years they reverted to a full-ported 2012-2015ish style even making the laptop fatter with the M1s. Maybe the phones will follow suite (yeah keep dreaming!).

      2. Then they could at least integrate a low-power FM stereo radio transmitter (~88-108 MHz), so we can listen to music wirelessly (in the car, via headphones w/ built-in radio). Classic bluetooth works, but has poor audio quality / little bandwidth. It’s merely the wireless equivalent to a quick RS-232 serial port, imho. I mean, almost all mobile phones outside of the states do have an FM radio built-in by now, albeit they require external headphones connected to the 3,5mm jack to work as an antenna.

      3. Breaking connectors = service income.
        Plugging stuff in the wrong way doesn’t happen anymore (USB-C)
        Water and cat fuzz aren’t a problem anyway, connectors are usually waterproof these days and are easily cleaned (service income again).

        As for hunting down cables – you’d still have to hunt down a charging pad, which is the same as a cable. And it would have to be a compatible charging pad, same as a cable (if not worse). And it would not be easy to find, while on travels, for $3.

        If you find any of that a problem, I worry for your bigger problems in life!

      4. At least throw the consumer a bone, and standardize two keyed holes on either side of the USB-C port on all phones that consumers can lock an add on flush-mount dongle onto. That way if I want a headphone jack, a USB-A port for a keyboard/mouse, or an HDMI port for video out, I just slap my dongle onto the bottom of the phone and I am golden. If I don’t need it, just take it off and my phone is smaller and consumes less power.

  10. I’d like to see a rundown of smartcards in general: how to interface with them and what they can do. The ones most people come across will be SIMs and EMV credit cards, but there have to be more kinds. The standard dates back to what, the late 80’s, early 90’s?

    1. JavaCard is another common one, and might be a good place to start digging. The physical and electrical specifications of all of these is standardized, and I think I remember the low level protocols being the same (though it’s been a while) and JavaCard had most of those details baked into it.

    2. You used see them used a lot as an additional method of ID verification, eg, for logging into a corporate bank account. As far as I could work out, they seemed to use some kind of certificate based process. Basically a form of 2 factor authentication, but before it was cool ;). You can even buy keyboards from Dell or HP which have a card reader built in, if you’re speccing up a business machine.
      I’m sure they’re still used in a lot of places, but I’ve not personally dealt with them since I left my old job.

  11. I prefer my old flip phone. In fact until Verizon shut down the 3g network in December of 2022 I was still using my 2003 Motorola V60s. I miss that phone. Simple and to the point with great audio. I have a smartphone now and I really don’t like it. If I wasn’t married, I’d just go without. Not a fan of the modern smartphone movement at all.

      1. I was going to see if there was a way I could get you not to comment, but it looks like there isn’t. I’m actually dealing with that pretty well. Quit being a slave to technology.

        1. I’m not a Luddite. I prefer simplicty in the technical things I use. I own smartphones and have learned how to do FRP removals, but I find them to be an incessant source of bother – like a petulant little kid. There is freedom when you’re not a slave to technology.

  12. With flaws like the recently revealed modem flaw in modern Samsung, google pixel and many cars modem software I’d say e-sim is a massive worry. As that chip must have access to the ‘esim’ data and with no user interaction, no need for physical access, just knowledge of a phone number and now your sim is whatever the hacker decides it is… And as the effected chipset is quite common for relatively modern devices it might well be worth it for the scumbags to just keep trying random numbers for the right global regions till they get a hit…

    At least if you physically loose the darn thing you know to watch your billing, report it when you get the chance, maybe order a replacement even after you find it again as a standard practice. And as the important bit of the sim in normal use isn’t writeable… (I don’t think it is anyway, no expert but I think the core network identify bits are not rewritable).

      1. Having it seems remote code execution on the modem chipset that must be able to read and likely write to the esim makes the esim potentially a problem – you phone will now priority connect to the network the hacker wants etc…

          1. Wouldn’t surprise me, it quite likely can just tell the SOC to run random code too – after all the modem has to wake the SOC and run the app the user will interact with this call/text from… But I don’t know nearly enough about these specific Modem SOC combinations.

  13. Don’t seems also store data about the Carrier Network like APN settings? I’ve had to upgrade my SIM over the years to be able to access things like HSDPA or LTE. T-Mobile is in the process of rolling out Standalone 5G and I believe you need to upgrade your SIM for it as well.

  14. Great article! 🙂👍

    Though I’m surprised no one made a comparison with a humble “telephone card” yet, since both SIM and telephone card were used by.. phones.
    Or maybe it’s just me. As a German, the credit card comparison was just weird. My first though was the telephone card, followed the cheque card.

    Also, I was waiting for the term “smartcard” to appear. One commenter named it so far, afaik, but it seems missing from the article.

    For example, one of the PIC16F84A’s predecessor, the PIC16C84, was available as a smartcard. A full fledged microcontroller! Up until the mid 2000s, the 16F84 was the equivalent to the ATMega168p/ATmega328p..

    And in the late 80s, early 90s, smartcard seemed unbelievable futuristic. Books were sold with diagrams from a logic probe, displaying what pulses go in/out, which duration they have etc.

    1. The only telephone cards I remember were magnetic strip cards, where the time available was either read and written to the mag strip, or the really early ones had a little mechanical chewer that destroyed the magnetic strip further as time ran out.

    1. Every worry of eSIM/iSIM was already done with normal SIMs. TMO and SPR already lock your phone to that specific card when activated, even if your phone is carrier unlocked. ATT/VZW allow you to swap cards on phones purchased from them, but only with other ATT/VZW cards respectively, and ATT will not let you unlock your phone until you completely remove it from your ATT account.

      eSIM/iSIM allow for SIM cards to be downloaded/disabled/enabled by the user just fine, just like normal SIM cards.

      1. FWIW, I have used TMO for a long time and never had trouble swapping my sim into any other compatible UNLOCKED phone I want to use. I have used anything from older foreign unlocked phones to stuff I bought online from everyone’s favorite online retailer that used to sell only books. As long as it’s unlocked, and has a compatible modem, I can drop it in and go. So the idea that you phone is locked to your account, at least with TMO, is pure FUD. It is regretful, but probably inevitable, that carriers would want control over you in another way. I, for one, will lament losing the ability to easily swap phones whenever I like. I’m sure it has something to do with the growing push for universal digital ID, which, sadly, will also be abused by corps and Governments the world over. SIGH!

  15. In North America we had GSM and CDMA, with the various cellphone companies split into two camps. GSM had the SIM card and with unlocked phones one could have multiple phones and move a SIM between them. So one could take a cheap dumbphone to the beach or gym or anywhere there was risk of damage, then swap the SIM to a fancy phone like a Palm Treo.

    The CDMA phones didn’t have such capability. The identity chip was built into the phone and switching phones on an account had to be done through the carrier. Some would allow the customer to switch as often as they wanted, some limited the number of switches per year, some didn’t allow switching or not without paying a fee.

    But in Europe and Asia CDMA phones did have SIMs, except they were called RUIM for Removable User Identity Module. Phones were available with up to four sockets, three SIM and one RUIM. None had more than one RUIM socket.

    The reason for that was insanely high roaming charges. It was less expensive to pay directly for phone service in different countries than to have service in one country and pay roaming charges. Travel outside your service area for one number? Switch to a different SIM or the RUIM without having to physically remove and replace anything.

  16. This is mainly a privacy issue. This tend to make the bond between the device and user identity even stronger. In my country, smartphone is slowly replacing the national identification card (with the app “Its me”). You need to prove your identity when you buy a phone number (pre pais cards).
    That is a very good way to be able to keep tracks of individuals. Even better than just wearing a GPS tracker.
    When you know the security level of smartphones, it is not only the government tracking problem, but GAFA and any other hackers.

  17. Buying a SIM in italy: A painful half and hour
    If I can install the eSIM by myself and have multiple ones in my phone, I say yes, eSIM for the win.
    Concerns: privacy, phone getting stolen/lost, more burocracy to register a SIM

  18. Then the smart guys in china will provide a sim card sized device that will be able to store the esim and allow the user to swap phones as they like … meaning the china produced smart phones that would otherwise not be usable unless the company paid the telecoms to deem them safe … which would be a hassle …

  19. I’m not sure how come so many folk are trimming sims, I find this pretty fascinating. My provider will send a replacement sim at the drop of a hat, for free, in whatever form factor I want (usually multi-punched to all sizes).

    1. I suppose that’s done by people who don’t have a contract. Here in Europe, you could buy a prepaid SIM card anonymously in a super market and use it. That has changed by now in some countries, but the principle still is the same. You can use that prepaid SIM without a contract, you can restore the credits on the SIM by buying special cards in super market. The downside is, that prepaid SIMs cannot be replaced, I think. If it breaks, you get no replacement, you loose your number, you’re on your own.

  20. “The first generation SIM cards were the same dimensions of a credit card[…]”
    “The first generation SIM cards were the dimensions of a credit card”
    “The first generation SIM cards were the same dimensions as a credit card”


  21. Meh. For the past 5 years or so, my phone number hasn’t been tied to a sim card, it’s been tied to a voip provider. Previously, and now (where it’s actually tied to a jabber account). Associating my phone number and account with a physical chip that ties that communications address to a physical device seems so.. primitive. I get a text or a phone call, it rings or messages all of my devices whether cell phone or laptop. I still do have *two* in use sim cards, but both are with a data-only plans (one for 5g home internet, and the other for a prepaid cell phone data plan), but I could care less if those sim cards disappeared or got lost.

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