SIM cards or Subscriber Identity Module as they are known in full.are a fundamental component of mobile phones. They are, in essence, a tiny chip that holds your phone number and connects your device to your chosen network. You can have SIM cards that are locked to particular networks or a Multi Network Data SIM like the ones from https://www.lister-communications.co.uk/business-mobiles/multi-network-data-sim-cards that are not locked into any one provider.

Mini SIMs were introduced in the early 1990s. These were a dramatic improvement on the large, bulky SIMs that were used in early mobile phones. This size of SIM card was standard for many years, but as mobile phones became smaller, there was a need for the cards to decrease in size also.

In the late 2000s, the Micro SIM was established. These were around half the size of the Mini SIMs, and they were able to be used in mobile phones, tablets and other portable devices. Again, these became the data card of choice for a period of time before, once again, mobile phones were slimmed down.

Next came the advent of the Nano SIM, which was introduced in 2012. These reduced the size of the SIM card even further, which allowed phone manufacturers to make thinner and more lightweight phones. These Nano SIMS have become standard in most mobile phones today.

Future innovations have allowed for eSIMs or Embedded SIMS to be developed. These are SIM cards that are integrated into a phone’s hardware and can be programmed remotely.