POS Entry Mode
What it is
How the PAN was captured (positions 1–2: keyed, magstripe, chip, contactless) and PIN capability (position 3).
Positions 1–2 describe PAN entry: 01 manual key entry, 02 magnetic stripe, 05 ICC (contact chip), 07 contactless EMV, 90 full magstripe read, 91 contactless magstripe. Position 3 describes PIN entry capability: 0 unspecified, 1 terminal can accept PINs, 2 terminal cannot.
Entry mode is a first-order input to interchange qualification, chip liability shift, and fraud scoring — a magnetic-stripe read of a chip card (80 fallback where the network defines it) gets particular scrutiny. Mastercard uses DE 22 with its own subfield tables; Visa aligns closely with the ISO base.
Example values
051Contact chip read, PIN-capable terminal.071Contactless EMV tap, PIN-capable terminal.011Manually keyed, PIN-capable (typical MOTO/fallback).DE 22 on the wire
Bitmap position
DE 22 is bit 22 of the primary bitmap: byte 3, mask 0x04. A primary bitmap with only DE 22 present reads 0000040000000000 in hex.
Length
DE 22 is fixed length: always 3 digits, with no length prefix. A parser reads exactly that many and moves on, so shorter values are right-aligned and padded with leading zeros.
Size in the message
At most 3 bytes when the message travels as text (ASCII or EBCDIC), or 2 bytes in binary dialects that pack digits as BCD.
Format n
Format n means numeric: the digits 0–9 only.
Specification reference
Defined in ISO 8583:1987 (base). Card networks publish their own dialect tables (Visa BASE I / V.I.P., Mastercard CIS) that refine formats, lengths, and — for private-use elements — the entire layout. Always confirm against the interface specification you implement.