You’ve just bought yourself an iPhone – welcome to the club! However, while you thought you’d just be able to pop your existing SIM card into your iPhone, you might be wrong. That’s dependant on not only which size SIM card you have, but model of iPhone you have too, as older iPhones use standard SIMs while more recent iPhones opt for the Micro- or Nano-SIM. Here, we explain the differences between SIM, Micro-SIM and Nano-SIM, and explain which size SIM you’ll need for your iPhone.  

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Which size SIM do I need for my iPhone: SIM, Micro-SIM and Nano-SIM

Before we explain which size SIM your iPhone requires, we thought we’d explain a little bit about the different sizes available. Let’s start off with the full-size SIM card, measuring in at 85.6 x 53.98mm, making it the largest currently available. While the standard SIM card had once been the go-to size for SIM cards, the recent trend in making technology in smartphones as compact as possible means that smartphones can’t provide enough room for the standard SIM – this is especially true of iPhones.

That’s why, starting with the iPhone 4, Apple decided to switch from the standard SIM to the Micro-SIM. The Micro-SIM was much smaller than the standard SIM measuring in at 15 x 12mm, making it ideal to fit into more compact smartphones. However, while the Micro-SIM is small, Apple (and other smartphone manufacturers) needed something smaller, so the Nano-SIM was developed.

The smallest SIM currently available, the Nano-SIM measures in at only 12.3 x 8.8mm, and is the standard for many 2016/2017 smartphones as it allows smartphone manufacturers to use as much available space as possible.

Now we’ve explained a little about the three types of SIM card available in the UK, let’s take you through the iPhone requirements to make sure you’ve got the right size SIM for your phone.

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Which size SIM do I need for my iPhone: iPhone, iPhone 3G, iPhone 3GS

For those with the original iPhone, an iPhone 3G or 3GS, you’ll need a standard SIM card. You can either call your mobile carrier and request one (they may charge you for this) or alternatively, you can buy a SIM card adaptor that’ll let you fit a Micro- or Nano-SIM into a standard SIM slot.

Which size SIM do I need for my iPhone: iPhone 4, iPhone 4s

But what about those with an iPhone 4 or iPhone 4s? You’ll need a Micro-SIM to use the smartphone, the second-smallest SIM card available. Those with a Nano-SIM that require a Micro-SIM can use a SIM card adaptor to bump it up, but what about those with a standard SIM? If you don’t want to speak to your mobile carrier about being sent a Micro-SIM, you can cut the standard SIM down to size. We can talk you through that process, simply head here: How to cut a SIM card for the iPhone

Which size SIM do I need for my iPhone: iPhone 5, iPhone 5s, iPhone 5c, iPhone 5s, iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, iPhone SE, iPhone 7 and iPhone 7 Plus

For those with an iPhone 5 or later, the Nano-SIM is the SIM card you’ll need. Unlike with the above options, users can’t opt for an adaptor because it’s larger than the size it needs to be. This means that you’re left with two options – cut it yourself, or call your carrier and request a Nano-SIM.