13.56 MHz HF Smart Cards

srix4k iso14443b card

13.56 MHz HF C-tier format

Genuine STMicroelectronics STMicro SRIX4K / ST25TB04K (ISO 14443B) supplied as an encodable blank — a 13.56 MHz contactless smart card you program for your own access-control, transit, NFC or hotel application. We stock genuine silicon and ship loose or pre-encoded, in bulk, at a fraction of retail pricing.

How the STMicro SRIX4K / ST25TB04K (ISO 14443B) works

The STMicro SRIX4K / ST25TB04K (ISO 14443B) is a 13.56 MHz high-frequency contactless credential read over the ISO/IEC 14443 air interface. The STMicro SRIX4K / ST25TB04K (ISO 14443B) is genuine STMicroelectronics silicon — data structure ISO 14443B; 4Kbit; transport/ticketing — the same chip platform the major lock, transit, hotel and payment systems specify.

We stock it as an encodable blank, supplied unprogrammed or pre-encoded to your specification, so your access-control system, card bureau or application writes it with your own data and keys — exactly as you would chips ordered through the STMicroelectronics distribution channel, at a fraction of the price. There is nothing aftermarket about the chip itself; what we add is sourcing, encoding and bulk availability.

Whether you need a handful of spares or a bulk run for a facility, transit programme or NFC project, tell us the exact STMicroelectronics chip and quantity and we confirm the part before production. Security ID Systems supplies genuine STMicroelectronics silicon and is independent and not affiliated with STMicroelectronics.

Also known as

SRIX4K · ST25TB04K · SRI4K · M067 · M110

STMicroelectronics and all other brand and product names are trademarks of their respective owners. Security ID Systems is an independent manufacturer and supplier of compatible access-control credentials and is not affiliated with, authorized by, sponsored by, or endorsed by these companies. Brand and format names are used only to identify the systems our products are compatible with. MIFARE and DESFire are registered trademarks of NXP B.V.

STMicro SRIX4K / ST25TB04K (ISO 14443B) — common questions

Are these genuine STMicroelectronics chips?

Yes — the STMicro SRIX4K / ST25TB04K (ISO 14443B) is built on genuine STMicroelectronics silicon, supplied as an encodable blank for your own system to program. It is an independently supplied access credential, not an STMicroelectronics-branded retail product; Security ID Systems is independent and not affiliated with STMicroelectronics.

Is the STMicro SRIX4K / ST25TB04K (ISO 14443B) supplied blank or pre-encoded?

Either. We ship genuine STMicroelectronics STMicro SRIX4K / ST25TB04K (ISO 14443B) unprogrammed for your own encoder, or pre-encode each one to your specification before it ships — useful for access-control, transit, campus, NFC and hotel programmes that issue in volume.

What frequency and chip is the STMicro SRIX4K / ST25TB04K (ISO 14443B)?

It operates on 13.56 MHz HF and is built on Genuine NXP MIFARE / DESFire, with a iso 14443b; 4kbit; transport/ticketing data structure. Matching the exact chip and memory layout your system expects is what makes it drop straight into your existing workflow.

Can you supply STMicro SRIX4K / ST25TB04K (ISO 14443B) in bulk?

Yes — bulk and reorder quantities are a core part of what we do. Tell us the exact chip, memory size and quantity, and we quote genuine STMicroelectronics silicon at a fraction of retail pricing, with your specification kept on file for fast reorders.

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Order genuine STMicro SRIX4K / ST25TB04K (ISO 14443B)

Send the part number or a photo of your card and reader. We verify the encoding before production and ship worldwide — including the rare formats no one else lists.