Here’s why Sim cards are getting smaller

In 2015, I got a new smartphone that unfortunately for me couldn’t accommodate the sim card I had been using at the time. I had to get the sim card cut so it could fit in the card slot of my new phone. The technician who cut the card called it a micro SIM. Two years later I got yet another phone and again I had to cut the sim card, this time the technician called it a nano SIM. It was smaller than it’s micro predecessor and I wondered why the SIM cards seemed to be getting smaller yet the phones were getting bigger and wider. If you have also wondered about this sim card phenomenon, here is a look at why it happened.

Back in 1991, the use of SIM cards became popular in communication devices and the first SIM card format was made available to the masses. It worked more or less like the SIM cards we have today. It was called the Full size SIM card a name it rightfully deserved because it was as large as an ATM card. This being 1991, that was probably as small as they could make it but it worked just fine.

A full size sim card. Photo by

In 1996, the second format of the SIM cards was rolled out and it would be the first attempt at making the cards smaller. The full size card was cut from a length of 85 mm (8.5 cm) to 25 mm (2.5cm) This is the SIM card we the early millennials grew up seeing and probably had in our first phone. (If you remember MTNs service fee then you know this one). It was called the Mini SIM.

Mini SIM cards

In 2003 the mini SIM card got cut again from 25 mm to 15 mm to give birth to the micro SIM card. It’s important to note that many of us got to use these much later because not many phone manufacturers supported them and they were popularised by the iPhone.

In early 2012, the sim card was downsized once again, this time from a length of 15 mm to 12 mm (1.2 cm) and it was called the nano SIM. This format of SIM card is what we commonly have today.

Transformation from mini to micro to nano SIM cards

Now that you know the history of the cards, the reason behind the reduction of the SIM cards is the need for space amidst technological advancement. Back in the day, when all that phones did was make calls, they could afford to have a sim card the size of an ATM card and it would not affect the phone’s performance, however, with phone manufacturers making smaller and thinner phones there was need to create space to fit more features into the phone such as a radios, motherboards and more fancy electronics hence the reduction in size to micro SIM cards to make room for additions to be made to the phones.

In the era of smart phones where the phones are able to do a lot more than before. There is a greater need to create space for features and therefore no reason to have a huge sim card. One of the largest challenges smart phone makers have is battery life. The bigger the battery they can fit in a phone, the longer the on-screen time a phone can achieve. It therefore makes a lot of sense to cut the size of the SIM card holder in the phone so as to get a few more millimeters of space for a larger battery or a stronger micro processor. It is important to make a small cut in size of the cards to make room for bigger changes to the phones.


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