What is a UICC (Universal integrated circuit card)

What is a UICC (Universal integrated circuit card)

Find out what is UICC, how it works, its components, and the many advantages of a universal integrated circuit card, the technology that powers the mobile communication revolution.

UICC is the technical name for the physical SIM card, it’s usually made from polyvinyl chloride (PVC) with the SIM as its primary component. UICC is used in mobile devices that use GSM, UMTS, and CDMA networks.

The international SIM cards we sell to global tourists at travSIM are based on UICC technology that has powered the mobile revolution for the last two decades.

1. What does UICC stand for?

UICC stands for universal integrated circuit card, it is a smart card that stores and protects data in a SIM device, it is made up of a CPU, ROM, RAM, EEPROM, and I/O circuits.

The universal integrated circuit card contains an IMSI number which is used to identify mobile subscribers and the services associated with their SIM plan.

A UICC is also referred to as a SIM, USIM, RUIM, or CSIM. If you want to find out more about SIM cards read our article on what is a SIM card and how it works.

2. Functions of a UICC

The UICCs primary component is a SIM card and the main functions of a UICC in devices with a subscriber identity module are listed below

  • Stores SIM card data
  • Helps mobile operators identify subscribers
  • Protects SIM card data
  • List of preferred networks
  • Contains software applications (SIM, USIM & CSIM applications)

Further reading: History of SIM cards

3. Components of a UICC

The main components of a UICC are listed below

  • RAM (Random access memory)
  • ROM (Read-only memory)
  • NVRAM (Non-volatile random access memory)
  • CPU (Micro-processor)
  • I/O circuits

4. What can be stored in a UICC?

The typical storage of a UICC ranges between 256 KB and 100 MB, it is this storage that is used to store other things

  • Subscriber information
  • Contacts
  • SMS
  • Security information
  • Network specific data
    • Integrated circuit card identifier (ICCID)
    • International mobile subscriber identity (IMSI)
    • Authentification key (Ki)
    • Local area identity (LAI)
    • Operator-Specific Emergency Number
  • Carrier specific data
    • SMSC number (Short Message Service Center)
    • Service Provider Name (SPN)
    • Service Dialing Numbers (SDN)
    • VAS applications

Further reading: What is a ICCID number & why it’s important.

5. Advantages of UICC

  • Works with both 3G or GG devices
  • Multiple applications
  • Enables communication over IP
  • Facilitates cross-network data roaming
  • Large storage capacity
  • Embedded microprocessor
  • More efficient
  • Enables mobile data across multiple carriers

Further reading: SIM card sizes, dimensions & types (2022 User guide).

6. How to UICC unlock a phone

A UICC lock is when a mobile device is locked to one mobile network or carrier, this means the phone cannot be used on any other network carrier unless the lock is removed.

To UICC unlock a phone there are three main options you have as outlined below

  • Online UICC unlock services
  • Third-party UICC unlock software
  • Mobile network carrier UICC unlock

7. Benefits of UICC unlock

UICC unlock has many benefits which include

  • No international roaming charges
  • Ability to choose the best carrier in your area
  • UICC secures your personal information

Further reading: What is a travel SIM card? (2022 international travelers guide)

8. What is the difference between UICC and eUICC

The major difference between UICC & eUICC is that UICC is a physical SIM card while eUICC is a software-based SIM. Find below the top major differences between these SIM technologies.

  • UICC contains a single MNO profile while eUICC can take a maximum of 8 MNO profiles
  • eUICC has remote provisioning while a UICC doesn’t
  • An eUICC uses more power than a UICC
  • UICC has a SMS-SR while the eUICC has a ISD-R
  • UICC architecture: IMSI, ICCID, PLMN list & Authentification keys
  • eUICC architecture: ISD-P4, ISD-P3, ISD-P2, ISD-P1, ECASD & ISD-R
  • eUICC stands for Embedded Universal Integrated Circuit Card while UICC stands for Universal integrated circuit card

Further reading: Benefits of a travel SIM card (2022 International tourist guide)


  • Is there a difference between UICC and a SIM card?
    • No there is no difference between a UICC and a SIM card, they are basically the same thing.
  • What is the full meaning of UICC?
    • UICC means Universal Integrated Circuit Card.
  • Do UICC SIM cards support UMTS networks?
    • Yes UICC SIM cards support UMTS networks
  • What are the other names for UICC?
    • UICC is also referred to as a physical SIM card, SIM, RUIM, USIM or CSIM?
  • Does a UICC support GSM networks?
    • Yes, UICC supports GSM networks via the SIM application.
  • How is UICC different from a SIM card?
    • There is no difference between a UICC and a SIM card.