FIX Protocol Tag 554: Password

Password used for authentication, for example in a Logon. Treat logs that contain it as sensitive.

Tag number: 554
Data type: STRING
FIX versions: FIX 4.3 to 5.0 SP2 and FIXT 1.1
Used in: 2 message types

Practical notes on Password

Password on the Logon, sent with Username (553).

FIX sends it as plain text inside the message, so the session must run over TLS or a private line.
From FIX 4.4 a Logon can also carry NewPassword (925) to change the password at logon.

Common mistakes

Writing the Logon to logs with the password in clear. Mask 554 and 925 in message logs.

Changes between FIX versions

In the Logon from FIX 4.3. FIX 5.0 adds encrypted password fields (1400 to 1402) on FIXT sessions.

Tag 554 in each FIX version

Values and message usage as defined in a specific version.

Data type

STRING: Text of printable characters. It cannot contain the SOH delimiter.

Example

554=********

Illustrative value. In a message, fields are separated by the SOH character (0x01), often shown as | or ^ in logs.

Decode a message with this tag

Message types that use tag 554

Logon 35=A
User Request 35=BE

Covers every version from FIX 4.0 to 5.0 SP2, including fields reached through components and repeating groups. The version pages above show whether the tag is required in each message.

Field and message data comes from the QuickFIX data dictionaries for FIX 4.0 to 5.0 SP2 and FIXT 1.1, used under the QuickFIX Software License. This product includes software developed by quickfixengine.org (http://www.quickfixengine.org/). Enumerated value names are converted to plain text for reading.