What size SIM do I need?

October 18, 2023

5 SIM cards stacked - eSIM, nano SIM, micro SIM, mini SIM

Micro SIM, nano SIM, eSIM – which SIM card size do you need? Read on to find out everything you need to know about different types of SIM card.

What is a SIM card? 

SIMs might not seem like much, but those little microchips are the beating hearts of our phones and tablets. Without them, calls, texts, and data use wouldn’t be possible.

And while they all work the same way and do the same job, SIMs also come in different sizes. 

Standard SIM

The “normal” sized SIM. It’s the one you probably remember from your first ever mobile phone. Launched in 1996, they’re only used in older phones and devices now – like the iPhone 3GS or Samsung Galaxy II. 

Micro SIM

As the name suggests, the micro SIM is a smaller version of the standard SIM. It’s about half the size at 15mm x 12mm. It was introduced in 2003 and was first used with iPhone 4. 

Nano SIM

At around 40% smaller than a micro SIM, the nano SIM is the smallest of the lot. It comes in at a tiny 12.3mm x 8.8mm.

We first saw the nano SIM in 2012 and Apple made it the standard SIM for every phone from iPhone 5 onwards.

It’s now the most common SIM size for most smartphones. So, if you’ve got a new iPhone 15 Pro, Samsung Galaxy S23 Ultra, or Google Pixel 7 Pro – you’ll be using a nano SIM.  

What about eSIMs?

Heard about eSIMs but not sure what they are? Well, they connect you to a network like a physical SIM but, they’re a virtual, electronic version. They let you activate your mobile data plan without needing to put a physical SIM into your device.

And they’re not just for phones and tablets, cellular smartwatches use eSIMs too.  That’s what lets you use Smartwatch Pairing where you can share your data, call, and text allowances with your smartwatch. 

With smartphone design advancing, lighter, slimmer, and even foldable phones are becoming more common place. And as they save valuable hardware space, it’s like that in time, most, if not all phones will use eSIMs. 

Plus, with no packaging or postage, eSIMs are not only cheaper to produce but they’re more environmentally friendly too.

What is a Data SIM card? 

A Data SIM can only be used for browsing, streaming, uploading, or downloading content. You can’t use it for calls or texts.

These types of SIM are usually used in tablets, iPads, Mobile Broadband, and Home Broadband devices. 

What size SIM do I need? 

Need to check the Samsung Galaxy S23 SIM size? Or maybe you want to know what size SIM an iPhone 12 takes? Check the list below to find out which size SIM you need: 

iPhone SIM card sizes

Samsung phone SIM card sizes 

What size SIM do I need for my iPad or tablet?  

Most tablets like the Samsung Galaxy Tab S7 FE use a nano SIM. But some like iPad Pro 6th Gen or the Samsung Galaxy S9 Ultra tablet can use both a nano and eSIM. 

Why have SIMs changed in size? 

It’s mainly down to advances in technology – a smaller SIM means you can have a thinner, lighter phone. You’d be surprised how the newly saved space can be used to cram in other impressive bits of hardware.  

Need a replacement SIM? 

If your SIM is the wrong size, getting a replacement is easy.

Just give us a call or go into any Three store. If you’re heading into your local store, don’t forget to take valid photo ID with you.

Pay Monthly account holders can also use our online request form to get a replacement SIM.

What about a SIM adapter? 

Need a bigger SIM? Instead of getting a completely new one, you’ve got the option to use a SIM adapter instead. This handy bit of kit lets you use a smaller SIM in a device that needs a larger one.

You can pick one up for free from any Three store or by giving us a call.

Want to know more? Check out this guide – How to use a SIM adapter

Getting a SIM Only card from Three 

You can use a Three SIM in any unlocked 4G or 5G phone or tablet.

Happy with your phone or tablet? We’ve got loads of SIM Only plans available too.

Not quite ready to commit to a Pay Monthly plan? Order your free Pay As You Go SIM today. And don’t forget, you can make your money go further with a Data Pack. Pick your data allowance and get unlimited minutes and texts included. Plus, get extra data on us when you auto-renew selected packs.

If you’re a Three Business customer, check out our Business SIM Only deals.