FIX Latest Online Specification
(as of EP258)
This is the starting page for FIX Latest, the specification of the application layer of the FIX Protocol. It provides the normative specification and is the successor of the previous specification documents “FIX Version 5.0 Service Pack 2 Specification with 20110818 Errata” (aka “Volume 1-7”). The previous specification documents also contained FIX Technical Standards (FIX tag=value, FIXML) as well as various guideline material that is not considered to be part of the normative specification. The online version of the normative specification is separate from the detailed layouts of the messages and components. The document version for download includes both in a single document.
FIX Technical Standard Specifications by FIX Protocol Ltd. are licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.
Data Types, User-Defined Fields, Global Components
Securities Reference Data
Market Structure Reference Data
Single General Order Handling
Order Mass Handling
Business Rejects, Network Status, User Management, Application Sequencing
FIX supports external code lists for certain fields. Code lists are maintained outside of the FIX Specification review process to support faster extensibility. A complete list can be found here.
User Defined Fields
The table on this page summarizes currently used custom fields. At this time, the available tag numbers in the user defined range of 5000 to 9999 have all been allocated.
FIX Algorithmic Trading Definition Language (FIXatdl) is an XML based standard to specify the user interface components for algorithmic trading. Please look here.
FIX Market Model Typology (MMT) initiative is a collaborative effort established by a broad range of industry participants (trading/reporting venues, data vendors and buy/sell side participants). The initiative is committed to achieving a practical and common solution for standards on post-trade data across all asset classes subject to MiFID II. Please look here for details.
Supported Legacy Versions
Unsupported Legacy Versions
The FIX Community discontinued support for earlier versions of FIX. The specifications are archived on the website and continue to be accessible.