Older Versions of FIX Protocol Specification Documents

FIX 2.7 Specification

FIX 2.7 Specification (No longer supported)
17 January 1995
First version of FIX used in production. Released January 17, 1995

FIX 3.0 Specification

FIX 3.0 Specification (No longer supported)
27 September 1995
Released September 27, 1995

FIX 4.1 Specification (Original)

FIX 4.1 Specification (Original release--Replaced by 4.1 Spec with Errata)
1 April 1998
Original 4.1 version released April 1, 1998

FIX 4.2 Specification (Original)

FIX 4.2 Specification (Original release--Replaced by 4.2 Spec with Errata)
14 August 2004
Original 4.2 version released March 1, 2000

FIX 4.3 Specification (Original)

FIX 4.3 Specification (Original release--Replaced by 4.3 Spec with Errata)
24 August 2001
Original 4.3 version released August 24, 2001

FIX 4.4 Specification (Original)

FIX 4.4 Specification (Original release--Replaced by 4.4 Spec with Errata)
30 April 2003
Original 4.4 version released April 30, 2003

FIX 5.0 Service Pack 2 (Original)

FIX 5.0 Service Pack 2 Specification (Original release--Replaced by 5.0 SP2 Spec with Errata)
18 August 2011
Original 5.0 Services Pack 2 version released April 20, 2009