What’s a SIM Card and How Does It Work?
What Is a SIM Card Used For?
Some phones need a SIM card to identify the owner and communicate with a mobile online grid.
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This is important in resale situations, where a used smartphone is missing a SIM card.
In many countries, SIM cards and devices are locked to the carrier the gear is purchased from.
It is usually possible tounlock a cellphonewith help from the carrier.
Does My Phone Need a SIM Card?
You might have heard the termsGSMandCDMAin relation to your smartphone.
GSM phones use SIM cards while CDMA phones do not.
However, in these situations, the identification features are not stored on the SIM.
To do that, you have toactivate the equipment from your Verizon account.
The SIM card on GSM phones can be swapped with other GSM phones.
Instead, the gear contained the identifying numbers and other information.
This card looks almost identical to a SIM card and works in most GSM devices.
What Does a SIM Card Look Like?
A SIM card looks like a small piece of plastic.
The important part is a small integrated chip that is read by the mobile gear it is inserted into.
The chip contains a unique identification number, the phone number, and other data specific to the user.
The first SIM cards were roughly the size of a credit card and were the same shape.
The iPhone 4 and 4S use the larger Micro-SIM card.
See SIM Local’sSIM Card Sizes tableto find which key in of SIM your phone uses.
Where Do I Get a SIM Card?
This is usually done through customer service.
How Do I Remove or Insert a SIM Card?
The process of replacing a SIM card varies depending on the rig.
It might be stored behind the battery, which is only accessible through a panel at the back.
However, some SIM cards are accessible on the side of the phone or mobile equipment.
Otherwise, refer to your phone’s support pages for specific instructions.
