Key Difference: SIM (standard) and Micro SIM are the same in terms of functionality. The only difference between the two is regarding their size. A micro SIM is nearly 52 percent smaller than the standard SIM.

SIM stands for subscriber identity module or subscriber identification module.  This card stores the information about network and telephone numbers in mobile phones. It provides the connectivity to a mobile network. It performs functions like identification of a subscriber, authentication of a subscriber, storage to store phone numbers and SMS, etc.

SIM and Micro SIM differ in the size. Generally, the standard size of the SIM remains the same for phones. It measures around two and a half centimeter long and one and half centimeter wide. Micro SIM is a SIM but of smaller size. The excess plastic is cut in order to get the smaller size. This is excess plastic which attached to the active part of the car, and therefore trimming it down does not effects the SIM.  It is nearly half the length of the standard SIM. It was first introduced for iPhone 4. It is basically the third version or third form factor of the SIM standard. It is important to note that SIM and Micro SIM hold the same amount of data.

These Micro SIMs were developed by European Telecommunications Standards Institute. They designed these SIMs for the devices which are too small to contain a standard SIM.These SIMs are mainly used in the latest iPhones which includes 4th version onwards. There is no difference in working of a standard and micro SIM. One can make calls, text and even use Internet in the same ways. Smartphones and devices like iPhone, iPad WiFi+3G and Nokia Lumia phones all use Micro SIMs. Micro Sims for iPad have capabilities for rendering data only services.

One can ask the mobile service provider to replace the SIM and copy all data. However, if one wants to do it without seeking any help from mobile service provider then it is always recommended to use a die cutter for downsizing the SIM. The instructions can be searched on internet. Standard SIMs are being used by most of the older model handsets, whereas most of the latest smartphones use micro SIMs.

One can easily determine the type of SIM required by the handset by either checking the handset manual or by checking the website of the handset manual. The best part of using Micro SIMs is that they are backward compatible. One can easily place these cards on a normal SIM adapter. A multi fit SIM can be used for obtaining a standard SIM or micros SIM.

Comparison between SIM and Micro SIM:

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