At HKCARD ELECTRONICS CO.,LIMITED, we supply sysmoISIM-SJA5 programmable SIM/USIM/ISIM/HPSIM cards for teams who actually need control of the UICC—developers doing modem bring-up, researchers working on 5G SA features, and operators running lab or private campus networks.

If your work involves SIMPersonalization and repeatable SIM Testing, this is the kind of card that saves time because it’s built to be changed, measured, and changed again using your own sim personalize tools.

What sysmoISIM-SJA5 is (in plain language)

The sysmoISIM-SJA5 is an ETSI/3GPP standards-compliant UICC that can act as:

  • SIM (2G)
  • USIM (3G/4G)
  • ISIM (IMS / VoLTE)
  • HPSIM (project-dependent usage)

It’s widely used in test environments and private networks because you can access and modify the card in a controlled way—without being locked into a “black box” profile.

Why engineers choose it for SIM Testing

In real labs, failures usually come from small differences: an EF file set slightly differently, a service bit enabled on one card but not the other, a mismatch in authentication algorithm, and so on. The sysmoISIM-SJA5 is popular because it lets you see and change those details.

Typical use cases:

  • Device and module R&D (attach, mobility, data session testing)
  • Private LTE / 5G campus network trials
  • Core network integration (EPC/5GC)
  • IMS / voice projects using Volte sim cards style setups (ISIM-based IMS parameters)
  • Automated regression where you need Rewritable SIM behavior

What you can customize (customer-controlled)

With the proper credentials and SIM Tools, you can modify most aspects of the card, including:

File system and services

  • Edit the content of almost any file (EF) on the card (except EF.ICCD)
  • Enable/disable services via:
    • EF.SST
    • ADF.USIM / EF.UST
    • ADF.ISIM / EF.IST
  • Enable/disable individual files
  • Remove or deactivate applications (for example, disable ISIM to use the card as a “USIM-only” profile)

Authentication and algorithms

  • Change authentication key material: Ki / K / OP / OPc
  • Select authentication algorithms such as:
    • MILENAGE
    • TUAK
    • COMP128v1 / v2 / v3
    • XOR-2G / XOR-3G

This is exactly the type of flexibility teams need when they are comparing core network behavior, validating SIM profiles, or building repeatable test vectors.

OTA and applet management (for advanced workflows)

For teams that manage cards at scale or want remote operations, sysmoISIM-SJA5 supports:

  • OTA interaction via SMS using provided OTA key material:
    • RAM (Remote Applet Management)
    • RFM (Remote File Management)
  • Applet management through a card reader using GlobalPlatform SCP02
    • install / remove / lock applets (project-dependent)

If you’re building a lab workflow around Writable SIM Cards and automation, these functions matter because they allow controlled changes without physically swapping cards.

Up-to-date 5G SA support (3GPP Release 17)

sysmoISIM-SJA5 is aligned with 3GPP Release 17, including newer 5G SA related files under ADF.USIM/DF.5GS. That’s useful when you’re testing modern 5G SA behavior and need the card to match current standards—not older “LTE-only” layouts.

Works well with popular open cellular stacks

The sysmoISIM-SJA5 was originally popular in Osmocom environments, but in practice it’s often used with many other network implementations, including:

  • open5gs
  • OpenAirInterface
  • srsRAN
  • Free5GC
  • Amarisoft
  • and others

For engineers, this matters because you can keep one card platform while switching network stacks during evaluation.

SIMPersonalization workflow: what you need on your bench

To get the most out of these cards, teams usually prepare:

  • A stable card reader and driver setup
  • Reliable sim personalize tools (scripts/templates + read-back verification)
  • A simple log of what profile was written to which card (basic traceability)

This is where the card shines: it behaves like a proper engineering component, not a one-time consumable.

Important notice (please read)

This product is intended for public/private mobile network operators and the research community.
As a normal subscriber, you cannot “clone” a carrier SIM identity onto this card, because you do not have the original secret key material (K / OPc). HKCARD does not support illegal cloning or misuse.

Form factors available

2FF / 3FF / 4FF on a full plastic card (1FF carrier)

The standard sysmoISIM-SJA5 format is a full plastic card that supports:

  • 2FF (mini)
  • 3FF (micro)
  • 4FF (nano)

This is practical because the 1FF carrier fits standard chip-card readers for programming, while the punch-out sizes work with almost any phone or modem.

MFF2 (solderable)

The sysmoISIM-SJA5-MFF2 uses the same chip/OS/profile, packaged as MFF2 for soldering onto PCBs—common in M2M and IoT products.

Availability note:

  • MFF2 is typically supplied as made-to-order for volume projects.

Volume orders: customized cards (MOQ 1000)

For quantity orders (typically 1000 cards and up), HKCARD ELECTRONICS CO.,LIMITED can deliver customized SIM cards with:

  • customer-specific profiles (IMSI/ICCID ranges, keys, EF configuration)
  • consistent batch delivery
  • customer card printing (artwork on both sides) where required

If you tell us your target network (LTE/5G SA, private/public), whether you need IMS/ISIM for VoLTE, your preferred SIM Tools, and the form factor (2FF/3FF/4FF or MFF2), we can recommend the most practical sysmoISIM-SJA5 supply option for your SIM Testing and SIMPersonalization workflow.

HKCARD ELECTRONICS CO.,LIMITED
Whatsapp/wechat:+8615817372512
Skype/Teams：byron1681
Email：byronhan@cardmfg.com

Free SIM Personalize Tools Download
HKCARD programmable 5G NR R16 SA USIM cards in 2FF/3FF/4FF, pySim/Open5GS compatible