ISO 14443

ISO 14443

ISO/IEC 14443 is the international standard for proximity contactless smart cards and identification cards operating at 13.56 MHz. It is the foundational standard for NFC Forum Type 2 and Type 4 tags, EMV contactless payments, electronic passports (ePassports), and the vast majority of deployed NFC systems worldwide. The standard defines everything from the physical RF interface to the transport protocol layer.

Standard Structure

ISO 14443 is organized into four parts:

• Part 1 -- Physical characteristics: Defines the card's physical dimensions (ID-1 credit card size), environmental durability requirements, and the operating frequency of 13.56 MHz.
• Part 2 -- RF power and signal interface: Specifies the RF field characteristics, modulation schemes, and bit encoding for both Type A and Type B. NFC-A uses 100% ASK with Modified Miller coding; NFC-B uses 10% ASK with NRZ-L coding.
• Part 3 -- Initialization and anti-collision: Defines how the reader discovers and selects individual cards when multiple cards are present in the field. Type A uses a bit-level anti-collision algorithm based on the UID; Type B uses a slotted ALOHA probabilistic algorithm.
• Part 4 -- Transmission protocol: Establishes the half-duplex block-transfer protocol (T=CL) for reliable data exchange after card selection. This layer supports data rates of 106, 212, 424, and 848 kbps.

Type A vs Type B

The two signaling variants offer different engineering trade-offs:

Type A is overwhelmingly dominant in consumer NFC applications. Chips like the NTAG 213, NTAG 216, and MIFARE DESFire EV3 all use Type A signaling.

Relationship to NFC

ISO 14443 is one of the base standards that NFC builds upon. The NFC Forum maps Type 2 tags (NTAG family) and Type 4 tags (DESFire family) directly to ISO 14443A. The NFCIP-1 peer-to-peer protocol also uses the ISO 14443A physical layer. Virtually every NFC-enabled device includes an ISO 14443 compliant reader as its foundational communication capability.