ExpireTime (FIX tag 126)

UTCTimestampFIX 4.4FIX 4.2

ExpireTime (tag 126) is an UTCTimestamp field defined in FIX 4.4 and FIX 4.2. It appears in 17 message types, always optionally.

At a glance

Tag: 126
Name: ExpireTime
Datatype: UTCTimestamp (String)
Format: YYYYMMDD-HH:MM:SS[.sss]
Dialects: FIX 4.4 and FIX 4.2
Messages: 17

What the specification says

FIX 4.4

Time/Date of order expiration (always expressed in UTC (Universal Time Coordinated, also known as "GMT") The meaning of expiration is specific to the context where the field is used. For orders, this is the expiration time of a Good Til Date TimeInForce. For Quotes - this is the expiration of the quote. Expiration time is provided across the quote message dialog to control the length of time of the overall quoting process. For collateral requests, this is the time by which collateral must be assigned. For collateral assignments, this is the time by which a response to the assignment is expected.

FIX 4.2

Time/Date of order expiration (always expressed in UTC (Universal Time Coordinated, also known as "GMT")

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

A real message using tag 126

NewOrderSingle · FIX 4.4

Tag	Field	Wire value	Meaning
8	BeginString	FIX.4.4
9	BodyLength	137
35	MsgType	D	Order – Single
49	SenderCompID	BOARTEAM
56	TargetCompID	COUNTERPARTY
34	MsgSeqNum	2
52	SendingTime	20240101-12:00:00.000
11	ClOrdID	ORD-10042
54	Side	1	Buy
60	TransactTime	20240101-12:00:00.000
40	OrdType	1	Market
126	ExpireTime	20240101-12:00:00.000
10	CheckSum	219

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 126 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
CollateralAssignment	AY	Optional	—	directly on the message body
CollateralRequest	AX	Optional	—	directly on the message body
CrossOrderCancelReplaceRequest	t	Conditional	—	directly on the message body
ExecutionReport	8	Conditional	Optional	directly on the message body
MarketDataIncrementalRefresh	X	Conditional	Optional	inside the MDIncGrp component
MarketDataSnapshotFullRefresh	W	Conditional	Optional	inside the MDFullGrp component
MultilegOrderCancelReplace	AC	Conditional	—	directly on the message body
NewOrderCross	s	Conditional	—	directly on the message body
NewOrderList	E	Conditional	Optional	inside the ListOrdGrp component
NewOrderMultileg	AB	Conditional	—	directly on the message body
NewOrderSingle	D	Conditional	Optional	directly on the message body
OrderCancelReplaceRequest	G	Conditional	Optional	directly on the message body
QuoteRequest	R	Optional	Optional	inside the QuotReqGrp component
QuoteRequestReject	AG	Optional	—	inside the QuotReqRjctGrp component
QuoteStatusReport	AI	Optional	—	directly on the message body
SettlementInstructionRequest	AV	Optional	—	directly on the message body
SettlementInstructions	T	Optional	—	inside the SettlInstGrp component

Wire format

A UTC date and time. The fractional-seconds part is optional, so two timestamps can be equal but not byte-identical. @boarteam/fix keeps the value as a string; format rules are checked by validate(), which reports validate/invalid-value rather than throwing.

Read tag 126 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[126];field?.name;   // "ExpireTime"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