The iSIM is coming: the SIM is about to vanish into your phone's processor

The SIM has always been one simple thing: a key that proves to a network you're allowed to connect. That key just keeps getting smaller and harder to lose, and the iSIM is the last stop on the journey.

SIM vs eSIM vs iSIM

Here’s a breakdown of the evolution of a SIM card:

1. A physical SIM is a key you carry. It's the little plastic chip you pop into a tray, and you can move it between phones or swap in a local one when you travel.
   
2. An eSIM is that key rebuilt as software, living on a tiny dedicated chip soldered inside your phone. You can't remove it. Instead, you download "keys" (what providers call profiles) over the internet. That's exactly what happens when you buy a travel eSIM and scan a QR code.
   
3. An iSIM goes one step further. There's no separate chip at all. The SIM's job is folded into the phone's main processor (the brain that runs everything else) in a locked, secure corner. If the eSIM is a keypad bolted next to your door, the iSIM is the lock built straight into the door frame. 

So what exactly is an iSIM?

An iSIM takes the job the SIM has always done and moves it inside the phone's main processor, into a locked, protected area, so there's no separate SIM chip left anywhere in the device. As the security firm Thales explains it, an eSIM still needs its own dedicated chip, whereas an iSIM builds that function into the processor itself and removes the need for any separate SIM space at all.

Crucially, an iSIM follows the same rules as an eSIM. It complies with the same GSMA specifications, which means it's programed remotely the same way. For users, that's the whole point: nothing about buying or installing a data plan changes.

Who's building it, and when

This isn't a concept floating around a lab. Vodafone, Qualcomm and Thales demonstrated the world's first iSIM smartphone back in January 2022, and Qualcomm and Thales unveiled the world's first GSMA-certified iSIM on a Snapdragon mobile platform in early 2023, clearing the way for commercial devices. Specialist firms like Kigen now supply the iSIM software that goes into chipsets and modules, and analysts note that big operators (AT&T, Vodafone and Deutsche Telekom among them) have shown even more enthusiasm for iSIM than they did for eSIM.

The early action is in machines, not phones: the technology shines in tiny devices where every millimetre and every cent counts, which is why the first wave is heavy on IoT - sensors, trackers, connected cars and wearables.

Why device makers love it

The appeal is simple. Removing a component frees up space and cuts cost. Folding the SIM, processor and radio into one unit significantly reduces the circuit-board footprint, the parts a manufacturer has to buy, and manufacturing cost. That space can go toward a bigger battery or a thinner design, and the savings add up fast when you're shipping millions of devices.

It also unlocks gadgets that were never going to have a SIM tray in the first place, smartwatches, earbuds, cameras, drones, letting far more of your kit carry its own connection.

How big is this going to get?

Very. Counterpoint Research expects more than 9 billion eSIM- and iSIM-capable devices to ship between 2024 and 2030, with iSIM-capable devices growing the fastest of any type, at roughly a 160% compound annual growth rate over that period. 

Looking further out, Counterpoint predicts iSIM will become the predominant type of SIM after 2028, with cumulative shipments reaching around 4 billion by 2030. ABI Research forecasts eSIM-enabled device shipments will top 633 million in 2026, driven by Chinese smartphone adoption and the rollout of the new machine-focused eSIM standard. The physical SIM, in other words, is on a clear path to retirement.

What it actually means for your trips

This is what matters for anyone who travels, so let's be precise about what changes and what doesn't.

• What doesn't change is the bit you actually touch. Because an iSIM uses the same remote provisioning as an eSIM, buying a travel data plan stays identical: you pick a destination, pay, and download the profile. Your favourite travel eSIM app keeps working exactly as it does today, the SIM just lives somewhere new inside the phone.
  
• What will change is the hardware around you. The SIM tray disappears for good, so the days of prying open a slot and fiddling with a tiny local SIM at the airport are ending. Phones get thinner or gain bigger batteries. And far more of your travel kit (watch, tablet, camera, even a rental car) can hold its own data profile.

Apple is already racing down this road - the thinnest iPhone yet shaved itself to 5.6 mm by leaving the SIM card behind entirely.

The bottom line: the iSIM is the SIM disappearing into the chip. There's nothing you need to do about it today, and when it arrives you probably won't even notice - except that your phone is a little thinner, the SIM tray is gone, and your travel data still loads with a tap.