What SIM Card Do I Need For My Phone?

Mobile phones come in all shapes and sizes and surprisingly so do the SIM cards that go inside them. With three different sizes of SIM cards in use in the UK, this probably has you asking what SIM card do I need for my phone?

Last updated: 23rd Oct 2018 at 4:59pm

What Are SIM Cards?

A SIM (Subscriber Identity Module) card is small circuit board that holds critical information such as your mobile phone number and your service provider/network. A few decades ago, SIM cards were the same size as a credit card. These days, SIM’s can be as small as your fingertip.

No matter what phone you have, if it doesn't have a SIM card, then you will need one in order for the phone to work. Likewise, if you have SIM card and it does not fit into the phone, then you will need a replacement sim.

What Are The Different SIM’s?

The three sizes that are still in use are identified as Standard, Micro and Nano.


Standard SIM Card – The standard SIM (sometimes called Regular SIM) isn’t often used but you might need one if you have an older phone or a basic phone (sometimes called a feature phone). A Standard SIM has dimensions of 25×15mm and there is a reasonable amount of plastic surrounding the gold-coloured circuit board.

Micro SIM Card – Introduced in June 2010, the Apple iPhone 4 was the first phone to use a Micro SIM. The card has the same size circuit board as a Standard SIM but the excess plastic surrounding this has been removed. A Micro SIM is sometimes supplied in what is known as a Combi SIM. A Combi SIM is a Standard SIM but the central part surrounding the circuit board is perforated. This allows you to push the central segment out, giving you a Micro SIM that has dimensions of 15×12mm.

Nano SIM Card – Released during October 2012, the Nano SIM was first used by the Apple iPhone 5. Most new smartphones use a Nano SIM, which has dimensions of 12.3×8.8mm.

Purely for your interest, we will also mention that there is a new type of SIM card being used in some products. For now, this does not include mobile phones but it may in the future:

e-SIM/eSIM – This is an embedded SIM, meaning that it is actually built into the device and cannot be removed. The Apple Watch Series 3 has an e-SIM so that it can be used as a stand-alone device. e-SIMs are also used in new EU 2018 models of car. The European Commission has insisted that they have an eSIM built in, so that anyone can contact the emergency services, in the case of an accident.

Which SIM Card Do I Need?

A common question that is asked is: What SIM do I need in my phone? Below, we highlight which SIM card works in each iPhone:

Apple Phones:

  • iPhone 4 and 4S – Micro SIM
  • iPhone 5 to iPhone 8 – Nano SIM
  • iPhone SE – Nano SIM
  • iPhone X – Nano SIM
  • iPhone XR – Nano SIM
  • iPhone XS – Nano SIM

Android Phones:

  • Samsung Galaxy S9 and S7 – Nano SIM
  • LG G7 ThinQ – Micro SIM
  • Samsung Galaxy Note 8 – Nano SIM
  • Google Pixel 2 – Nano SIM Card & eSIM
  • Nokia 6 – Nano SIM

If you have another phone then you can take a look at the instruction manual for your phone to identify which SIM card is needed.

If you order a new SIM card from Asda Mobile then we will send you all three sizes of SIM, to ensure you get the card that you need.

Where is the SIM Card Slot Located?

When your new SIM card arrives, you will need to put it in the phone. The SIM card slot is usually in one of three places:

  1. Under The Back Cover – If the back cover is removable then the SIM card slot may be visible straight away.
  2. Under The Battery – If the battery is removable then the SIM slot may be under this.
  3. Exterior SIM Card Slot – If you notice a little cover on the side of the phone with a small hole in it, then this may be the SIM card holder.  You can use the SIM ejector tool that is supplied with the phone or a pin to eject the holder. Sometimes these are multi-function holders that also have a slot for you to insert a microSD memory card.

The SIM card is usually inserted with the circuit board facing down. All SIM cards have a 45-degree notch in one corner and this means that the card can only be inserted one way.

Asda Mobiles SIM Only Bundles

We have some really great news for you next. You can order your Free SIM Today from Asda Mobile. There are no sizing issues with Asda Mobile as we send out a card that includes all three sizes.

If you have a mobile phone number with another network, then you can bring this with you when you join Asda Mobile. To find out how Click Here.

We have lots of super sim only deals to suit everyone's needs. If you want to pay monthly without a contract and you are looking for fantastic offers on minutes, texts and data you can take a look at our 30 Day Bundles Here.

We aim to deliver your SIM card on the next working day, if you place your order before noon on Mon-Fri.

You May Also Like:

Still not sure?

No contract, no limits.

With no contract you have the freedom to flex your usage whenever you need to

Roam like you're home

Use your bundle in 50 European destinations for no extra cost.

Speed and Reliability

Powered by the nations largest network you can relax knowing you have the best coverage

Here's what people say

The lady i dealt with was excellent, she could not have been more helpful, i am very pleased and very impressed, she was wonderful, thank you very much. Allan, Cumbernauld

The advisor on the phone today was beyond helpful and assisted in every possible way he could! And got the job done. Amazing accent too!!!!!! X Jane, Huddersfield

You are better than O2 staff as it takes for ever to get through to some one Oliver, Hanna ballymatin

Excellent service. Friendly, patient and efficient. Made things very easy for me. Robin, Horam