IOIRefID (FIX tag 26)

StringFIX 4.4FIX 4.2

IOIRefID (tag 26) is a String field defined in FIX 4.4 and FIX 4.2. It appears in 1 message type, always optionally.

At a glance

Tag: 26
Name: IOIRefID
Datatype: String
Dialects: FIX 4.4 and FIX 4.2
Messages: 1

What the specification says

Reference identifier used with CANCEL and REPLACE, transaction types. (Prior to FIX 4.1 this field was of type int)

Descriptions are quoted from the FIX Orchestra sources under the Apache 2.0 licence.

A real message using tag 26

IOI · FIX 4.4

Tag	Field	Wire value	Meaning
8	BeginString	FIX.4.4
9	BodyLength	100
35	MsgType	6	Indication of Interest
49	SenderCompID	BOARTEAM
56	TargetCompID	COUNTERPARTY
34	MsgSeqNum	2
52	SendingTime	20240101-12:00:00.000
23	IOIID	EXAMPLE
28	IOITransType	N	New
26	IOIRefID	EXAMPLE
54	Side	1	Buy
27	IOIQty	S	Small
10	CheckSum	005

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.

Where tag 26 appears

Requiredness is a property of the message, not of the field: the same tag can be optional in one message and conditionally required in another.

Message	MsgType	FIX 4.4	FIX 4.2	Where in the message
IOI	6	Conditional	Optional	directly on the message body

Wire format

Free-form text. Any byte except the SOH separator is legal, so values are not trimmed or case-folded on the wire. @boarteam/fix keeps the value as a string; format rules are checked by validate(), which reports validate/invalid-value rather than throwing.

Read tag 26 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);const field = message.fields[26];field?.name;   // "IOIRefID"field?.raw;    // the verbatim wire stringfield?.value;  // coerced to a string

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

Try the decoder Source on GitHub