In recent years most manufacturers optimised their collection of mobile devices from Standard SIMs to smaller SIMs. If you are buying a mobile phone made in the last 8 years, chances are you’ll require at least a Micro SIM to use it.

However, most recent higher-end phones by major brands like Samsung, Apple, Huawei, Sony, and Xiaomi mainly use Nano SIMs. “Why is that?” you may ask, and it’s because phone manufacturers are constantly updating their devices with new features and larger batteries. So, they reduce the amount of space SIM cards occupy to create more room for these upgrades.

But your device doesn’t restrict which plans you can purchase as all networks support different SIM card sizes, so regardless of whether you have a PAYG plan, a SIM only 4G tariff or an unlimited data plan with a network you’ll be able to find a SIM card that can fit.

Currently there are three types of SIM cards in use. There’s the Standard SIM, the smaller Micro SIM and the smallest of them all the Nano SIM. The type of SIM Card you need completely depends on the mobile device you have. However, there are still some ways you can make a SIM card work with whatever phone you have. Also, most mobile networks in the UK send out SIMs in a 3-in-1 card, so you can just pop out the SIM size which fits your handset.

What is a Standard SIM card?

The Standard SIM card is the oldest and largest of the three types of SIM. It’s generally used in phones prior to 2010, there are of course some exceptions. The Standard SIM measures 25x15mm and it’s also known as 2FF.

You barely see a phone with a Standard SIM nowadays, but it’s sometimes found on basic feature phones.

What is a Micro SIM card?

The Micro SIM card is technically a Standard SIM card, but without the extra plastic around the circuit board. The only real difference between a Standard SIM and a Micro SIM is the size of the plastic around the microchip. Micro SIM was developed to make smartphones slimmer and lighter. High-end brands like

Apple and Samsung were the first to introduce the Micro SIM chip into the mobile market. It is also called 3FF. The Micro SIM measures 15x12mm.

The Micro SIMs were introduced back in 2010 and they’re still being used today. For example Samsung Galaxy S5, Galaxy J2 Pro and LG G4 and many other devices use Micro SIMs.

What is a Nano SIM card?

Pretty much all the latest devices from all manufacturers use Nano SIM cards. The Nano SIM card is the smallest one, almost 50 % smaller than a Micro SIM. It made its first appearance in the Apple iPhone 5. A Nano SIM measures 12.3×8.8mm.

What is a Combi SIM then?

Remember when we said the only difference between the Standard SIM and the Micro SIM is their size. The Combi SIM is basically a Micro SIM card within a Standard SIM-sized unit. If your phone requires a Micro SIM you just break the additional plastic away, and that’s it.

What is a 3-in-1 SIM card?

3-in-1 SIM Cards come with a Nano SIM card, as well as Micro & Standard SIM adapters. This way once you receive your SIM card you can just slip it into your phone and your device will be ready to go.

The only difference between the Standard SIM and the Micro SIM is their size. You can even cut the plastic around the Standard SIM and turn it into a Micro SIM. Of course, you should cut it carefully and safely, but we don’t recommend doing it, as you can get a free SIM from your network anyway.
Here’s a table below that shows the dimensions of each of the SIM types

Nano SIMs are significantly smaller and many phone manufacturers have made numerous devices that are only compatible with the Nano SIM. Thankfully there are adapters, so you can easily turn your Standard or Micro SIM into a Nano SIM. It’s also possible to cut a Mini SIM or Micro SIM all the way down to the Nano SIM size with a sharp pair of scissors.

Also, some networks like O2 might require you to change your current SIM card if you want to get 5G coverage. You can read our O2 Review to learn more about the network’s special SIM cards and their deals. Mobile virtual networks (MVNO) like Tesco Mobile & Sky Mobile are also powered by O2, and they’ll ask you to get a brand new SIM to access their special perks.

Read our Sky Mobile Review and discover what the carrier offers with a free SIM.

How to change a Standard SIM to smaller ones (Micro or Nano)?

Many SIM only and PAYG packages now offer 3-in-1 SIM cards. This means that the Standard SIM has both the Micro and Nano SIMs incorporated into it. Alternatively, as we stated above you can also trim your Standard SIM to become a Micro SIM with a pair of sharp scissors, after using a sharp knife to score where you need to cut from the SIM. Then you can use a nail file to smoothen the edges. This process takes a lot of patience as there is the risk of damaging your SIM with any scratch to the panel area. We’d again suggest getting a free new SIM from your network. You can get a free SIM without having to undergo a credit check with most MVNOs and PAYG plans. If you’re interested in a wallet friendly SIM deal we’d recommend you to check out our Three Review, SMARTY Review and Superdrug Mobile Review. Alternatively you can read our Three vs SMARTY comparison too!

With Black Friday being just around the corner, we’d also recommend checking our Black Friday SIM Only Deals before you make your final decision on a phone.

Apple smartphone models and SIM typesPhone

Samsung smartphone models and SIM types

LG smartphone models and SIM types

Huawei smartphone models and SIM types

Google smartphone models and SIM types

Xiaomi smartphone models and SIM types

BlackBerry smartphone models and SIM types

Motorola smartphone models and SIM types