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ISO 8583 Data Element Reference Guide

Technical specification, message structure, formatting rules, and Data Element (DE) dictionary.

Data Types
  • a – Alphabetic characters
  • n – Numeric values only
  • s – Special characters
  • an – Alphanumeric
  • ans – Alpha, numeric & special
Field Length Encodings
  • Fixed – Exact byte length
  • LLVAR – 2-digit length prefix (00–99)
  • LLLVAR – 3-digit length prefix (000–999)
Bitmaps
  • Primary Bitmap: DE1 – DE64
  • Secondary Bitmap: DE65 – DE128
  • Tertiary Bitmap: DE129 – DE192
Common MTI Formats
  • 0100 / 0110 – Authorization Req/Rsp
  • 0200 / 0210 – Financial Req/Rsp
  • 0800 / 0810 – Network Mgmt Req/Rsp
ISO 8583 Data Element Dictionary
Field Data Element Name Format Length Description & Operational Context
Core Transaction Data Elements
MTI Message Type Identifier n 4 Fixed (4) 4-digit code classifying overall message intent (Position 1: Version, Position 2: Class, Position 3: Function, Position 4: Origin).
DE1 Bit Map, Extended b 64 Fixed (8) Binary bitmap indicating presence of secondary fields (DE65 through DE128).
DE2 Primary Account Number (PAN) n ..19 LLVAR (19) Cardholder payment card number (13 to 19 digits). Must be masked/PCI-DSS compliant in logs.
DE3 Processing Code n 6 Fixed (6) 6-digit numeric code specifying Transaction Type (2 digits), From Account (2 digits), and To Account (2 digits).
DE4 Amount, Transaction n 12 Fixed (12) Transaction amount expressed in minor currency units (e.g., $100.00 = 000000010000).
DE7 Transmission Date & Time n 10 Fixed (10) Timestamp formatted as MMDDhhmmss (GMT/UTC switch time).
DE11 System Trace Audit Number (STAN) n 6 Fixed (6) Unique sequence number assigned by message originator to identify transaction requests/responses.
DE12 Time, Local Transaction n 6 Fixed (6) Local transaction time formatted as hhmmss.
DE13 Date, Local Transaction n 4 Fixed (4) Local transaction date formatted as MMDD.
DE14 Date, Expiration n 4 Fixed (4) Card expiration date formatted as YYMM.
DE22 POS Entry Mode n 3 Fixed (3) Identifies input method (e.g., 02=Magnetic Stripe, 05=EMV Chip, 07=Contactless, 01=Manual Keyed).
Merchant, Terminal & Response Elements
DE37 Retrieval Reference Number (RRN) an 12 Fixed (12) Universal transaction reference generated by acquirer/switch for lifecycle matching and chargebacks.
DE39 Action / Response Code an 2 Fixed (2) 2-character issuer response status code (e.g., 00 = Approved, 05 = Do Not Honor, 51 = Insufficient Funds).
DE41 Card Acceptor Terminal ID ans 8 Fixed (8) Unique terminal identifier deployed at merchant point of sale location.
DE42 Card Acceptor Identification Code ans 15 Fixed (15) Unique Merchant ID (MID) assigned by acquiring bank.
DE43 Card Acceptor Name/Location ans 40 Fixed (40) Merchant Name, City, State, and Country Code printed on cardholder statements.
DE49 Currency Code, Transaction a/n 3 Fixed (3) 3-digit ISO 4217 numeric currency code (e.g., 840 = USD, 978 = EUR, 356 = INR).
Private, Network & Reserved Data Elements
DE48 Additional Data (Private) ans ...999 LLLVAR (999) Proprietary container for network-specific TLV (Tag-Length-Value) structures, CVV2 checks, and fraud scoring data.
DE60 POS Terminal Data / Private ans ..99 LLVAR (99) Carries terminal capabilities, encryption indicators, and transaction environment sub-fields.
DE90 Original Data Elements n 42 Fixed (42) Used in Reversals/Refunds (0400/0220). Encapsulates Original MTI, STAN, Transmission Date/Time, Acquirer ID.
DE128 Message Authentication Code (MAC) b 64 Fixed (8) Cryptographic hash/HMAC generated over message fields using shared secret keys to guarantee payload integrity.
Standard ISO 8583 Response Codes (DE39 Quick Cheat Sheet)
00 – Approved / Honored
05 – Do Not Honor
51 – Insufficient Funds
54 – Expired Card
59 – Suspected Fraud
30 – Format Error
91 – Issuer / Switch Unavailable
96 – System Malfunction