Difference between 64K and 128K SIM Cards

What is a SIM Card?

SIM stands for Subscriber Identity Module or Subscriber Identification Module. It is a very small chip that is nearly equal to the memory card in terms of size, and it recognizes the user uniquely to the mobile network. With this small chip, users can use the various functions like calling, messaging, and internet access. SIM card has their own memory, which contains the details about the user like contact lists, identity, phone number, and text messages.

SIM cards work on different voltages like 5V, 3V, and 1.8V. SIM cards that were designed before 1998 supported only 5V, and then SIM cards started supporting both 5V and 3V. Nowadays, SIM cards can support 5V, 3V, and 1.8V. The latest SIM cards use SIM Application Toolkit to communicate with the handset to load the application on the device while they are in use.

As we have discussed earlier, a SIM card is capable of storing some details, so it has its own memory. The 'K' defines the memory of a specific SIM card in kilobytes. For example, a 64K SIM card contains a memory of 64 kilobytes, and a 128K SIM card contains a memory of 128 kilobytes.

If a SIM has a higher memory size, the most recent manufacturing it will represent. Nowadays, SIM cards of 128K or above have their own tracking features, so they can be tracked if they are lost.

Types of SIM cards

Full size SIM cards

This SIM card was developed in 1991 and had the size nearly to a credit card. Later the size was reduced to make it more compact. It is also called 1FF, which means the first form factor.

Mini SIM cards

Mini SIM was launched in 1996, and it is also called a normal or regular SIM. It has the same size as a full size SIM card, but it can be divided into some smaller parts for those devices which supports mini SIM and arranged together to make a full SIM card. It is also called 2FF, which represents the second form factor.

Nano SIM cards

In the physical size, a nano SIM card is generally smaller than normal, but it works the same as a normal SIM card. We can use a normal SIM card slot and out the nano SIM card by using the nano SIM adapter.

Nowadays, we use Embedded SIM, which is also known as e-SIM.

Prepaid SIM cards

This type of SIM card is pre-loaded with some amount of balance which is used for messaging, calling, and internet charges with some standard rates. If the preloaded amount is zero, we cannot use the functionality and we have to recharge it again.

Difference between 64K and 128K SIM Cards

64K SIM Card	128K SIM Card
64K SIM card can store a contact list of around 450 to 500 people.	128K SIM cards can store up to 600 people in their contact list. Generally, it depends upon the service provider.
It does not have a computer Synchronization feature.	128K SIM card provides the feature of computer synchronization
If any mobile device is lost or theft we cannot recover data in a 64K SIM card	If any incident of theft or mobile loss happens, then we can get the data recovery in 128K SIM cards.
The storage space given by this is 64 kilobytes.	A 128K SIM card provides 128 kilobytes of memory space.
It was used by many people before 2003.	After 2003, the number of users of 128K SIM cards has increased.
3G and 4G data services are used in 64K SIM cards.	4G services are mostly used in the 128K SIM cards.
Due to less storage, network operators can perform very few or limited operations on the 64K SIM cards.	Due to enough storage, mobile network operators can perform a good amount of operations on 128K SIM cards.
Due to limitations, there may or may not be some features in this SIM, like auto roaming, SMS lock, or direct access to social networking accounts, etc., which completely depends upon the network provider.	This SIM card has mandatory features of auto roaming, SMS lock, or direct access to social networking accounts, irrespective of the network provider.