ListCancelRequest (MsgType K)

applicationFIX 4.4FIX 4.2

ListCancelRequest is the FIX message with MsgType K, defined in FIX 4.4 and FIX 4.2. It is an application-level message: it carries a business event rather than managing the session. Its body has 9 top-level members once the standard header and trailer are counted.

MsgType is case-sensitive
K is ListCancelRequest, but k is a different message entirely — BidRequest. Twenty-three FIX message types differ from another only by letter case.

A real ListCancelRequest

ListCancelRequest · FIX 4.4
TagFieldWire valueMeaning
8BeginStringFIX.4.4
9BodyLength99
35MsgTypeKList Cancel Request
49SenderCompIDBOARTEAM
56TargetCompIDCOUNTERPARTY
34MsgSeqNum2
52SendingTime20240101-12:00:00.000
66ListIDEXAMPLE
60TransactTime20240101-12:00:00.000
10CheckSum056
Edit and decode it yourself

Shown with | separators for readability. On the wire FIX uses SOH (0x01), an invisible control byte — and because BodyLength and CheckSum are computed over the actual bytes, the two forms have different checksums. Both are valid and both decode here.

Open in the full decoder →

Generated from the FIX 4.4 dictionary and verified at build time: it parses and validates with no issues. Open the decoder to try your own message.

Message body — FIX 4.4

Components are listed by name and link to their own page rather than being expanded inline; repeating groups are expanded, including where they nest.

Message body — FIX 4.2

Components are listed by name and link to their own page rather than being expanded inline; repeating groups are expanded, including where they nest.

What changed between the dialects

Present in FIX 4.4 only (2)

tag 229, tag 75

Handle ListCancelRequest in TypeScript

decode.tsts
import { createFixEngine } from "@boarteam/fix";import { dictionary } from "@boarteam/fix-dict-fix44";const fix = createFixEngine(dictionary);const { message, issues } = fix.parse(raw);if (message.msgType === "K") {  message.name;            // "ListCancelRequest"  // fields are keyed by tag; repeating groups live on message.groups}// Problems come back as data, never as exceptions:issues;                    // FixIssue[]fix.validate(message);     // dictionary-level problems

Decode this in your own code

The same engine that produced the decoded example above is an Apache-2.0 npm package with zero runtime dependencies. It runs in Node and in the browser, and parse() returns problems as data instead of throwing.

npm i @boarteam/fix @boarteam/fix-dict-fix44