FIX-over-TLS (FIXS) is the standard to secure FIX sessions using the Transport Layer Security (TLS) protocol. The use of FIXS is considered a requirement as it introduces a basic level of security and standard options for interoperability.

Discussion on Cybersecurity  and FIXS can be found in our forums under General Q&A using the tag cybersecurity.

More information on the work from the FIXS Working Group can be found here.

Version 1.1 Release Candidate 1


FIXS - Technical Proposal - v1.1 RC1

392.92 KB 295 downloads February 22, 2021
Technical Proposal FIXS Version 1.1 Release Candidate 1– published February 22nd,...

FIXS - Technical Specification v1.1 RC1

455.82 KB 213 downloads February 22, 2021
FIXS Version 1.1 Release Candidate 1 – Technical Specification published February...

    Version 1.0 Standard


    FIXS Technical Specification – Technical Standard

    668.95 KB 117 downloads February 19, 2021
    2/19/2021 - FINAL Standard FIX-over-TLS (FIXS) v1.0 ...

      Version 1.0 Draft Standard

      Please find below the FIXS Draft Standard documentation.


      FIXS Technical Specification - v1.0 Draft Standard

      200.84 KB 1097 downloads January 6, 2018
      1/5/2018 -  Draft Standard v1.0 ...

        Version 1.0 Release Candidate 1


        FIXS Technical Standard - v1.0 RC1

        252.09 KB 1227 downloads August 18, 2017
        FIX-over-TLS (FIXS) Technical Standard - FIXS is the standard to secure the Transport...

          FIXS Stunnel User Guide for FIX Applications

          Please click here to view the technical guidelines for FIXS Stunnel.  The Stunnel guide is intended to allow anyone to get started with FIXS, whilst the FIXS specification is applicable to all TLS implementations.