A SIM is an integrated circuit that stores all kinds of data on mobile phones and even some computers. Used to not only store the information but also identity with a mobile provider, the two go hand-in-hand. Mini SIM cards were introduced in the late 90s and fit most mobile phones. They run approximately 25×15×.76 mm in size and can be transferred between devices seamlessly which has made the process of switching information between phones nearly effortless.
Today, SIM cards are manufactured to be a very discrete component of the phone. For many years, there were only traditional SIM cards, and now we have mini SIM cards and even smaller versions for various models. SIM cards used to take up a layer of the back of the phone, usually somewhere around the battery. Today, mini SIM cards are slid in a metal sleeve barely visible to the eye. It has all the same contacts as a regular SIM card, just smaller in stature.
Many SIM cards including mini SIMs can be purchased online. Mini SIM cards are designed for newer phones, but they can still be used in old phones that have a SIM card slot, so long as you have the original sheet used for the contacts. It’s not a definite solution, though, and it’s best to not guess at this. Few providers sell mini SIM cards at the moment due to the ever-shrinking size and advancing technology of micro and nano SIMs.
Mini SIM cards are still helpful tools for transferring data between phones, and they may be used on newer phones too. If you’re handy with tools and technology, you can always learn how to cut a mini SIM card down to size for a micro-fit, but be careful—losing all of that data would be a real shame.