NestedPartyRole (FIX tag 538)

intFIX 4.4FIX 5.0 SP2

NestedPartyRole (tag 538) is an int field defined in FIX 4.4 and FIX 5.0 SP2. It appears in 22 message types, always optionally.

At a glance

Tag: 538
Name: NestedPartyRole
Datatype: int
Dialects: FIX 4.4 and FIX 5.0 SP2
Messages: 22

What the specification says

FIX 4.4

PartyRole value within a nested repeating group. Same values as PartyRole (452)

FIX 5.0 SP2

PartyRole value within a nested repeating group.

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

A real message using tag 538

NewOrderSingle · FIX 4.4

Tag	Field	Wire value	Meaning
8	BeginString	FIX.4.4
9	BodyLength	169
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
78	NoAllocs1 entry	1	repeating group
79	AllocAccount	EXAMPLE
539	NoNestedPartyIDs2 entries	2	repeating group
524	NestedPartyID	EXAMPLE
538	NestedPartyRole	1
524	NestedPartyID	EXAMPLE
538	NestedPartyRole	1
54	Side	1	Buy
60	TransactTime	20240101-12:00:00.000
40	OrdType	1	Market
10	CheckSum	142

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 538 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 5.0 SP2	Where in the message
AdjustedPositionReport	BL	—	Optional	inside PositionQty › NestedParties
AllocationInstruction	J	Conditional	Optional	inside AllocGrp › NestedParties
AllocationInstructionAck	P	—	Optional	inside AllocAckGrp › NestedParties
AllocationInstructionAlert	BM	—	Optional	inside AllocGrp › NestedParties
AllocationReport	AS	Conditional	Optional	inside AllocGrp › NestedParties
AllocationReportAck	AT	—	Optional	inside AllocAckGrp › NestedParties
ApplicationMessageRequest	BW	—	Optional	inside ApplIDRequestGrp › NestedParties
ApplicationMessageRequestAck	BX	—	Optional	inside ApplIDRequestAckGrp › NestedParties
AssignmentReport	AW	Conditional	Optional	inside PositionQty › NestedParties
CrossOrderCancelReplaceRequest	t	Conditional	Optional	inside SideCrossOrdModGrp › PreAllocGrp › NestedParties
ExecutionReport	8	Conditional	Optional	inside InstrmtLegExecGrp › NestedParties
MultilegOrderCancelReplace	AC	Conditional	Optional	inside LegOrdGrp › NestedParties
NewOrderCross	s	Conditional	Optional	inside SideCrossOrdModGrp › PreAllocGrp › NestedParties
NewOrderList	E	Conditional	Optional	inside ListOrdGrp › PreAllocGrp › NestedParties
NewOrderMultileg	AB	Conditional	Optional	inside LegOrdGrp › NestedParties
NewOrderSingle	D	Conditional	Optional	inside PreAllocGrp › NestedParties
OrderCancelReplaceRequest	G	Conditional	Optional	inside PreAllocGrp › NestedParties
PositionMaintenanceReport	AM	Conditional	Optional	inside PositionQty › NestedParties
PositionMaintenanceRequest	AL	Conditional	Optional	inside PositionQty › NestedParties
PositionReport	AP	Conditional	Optional	inside PositionQty › NestedParties
Quote	S	Conditional	Optional	inside LegQuotGrp › NestedParties
QuoteRequest	R	Conditional	Optional	inside QuotReqGrp › QuotReqLegsGrp › NestedParties
QuoteRequestReject	AG	Conditional	Optional	inside QuotReqRjctGrp › QuotReqLegsGrp › NestedParties
QuoteResponse	AJ	Conditional	Optional	inside LegQuotGrp › NestedParties
QuoteStatusReport	AI	Conditional	Optional	inside LegQuotStatGrp › NestedParties
RegistrationInstructions	o	Conditional	Optional	inside RgstDtlsGrp › NestedParties
TradeCaptureReport	AE	Conditional	Optional	inside TrdInstrmtLegGrp › NestedParties
TradeCaptureReportAck	AR	Conditional	Optional	inside TrdInstrmtLegGrp › NestedParties

Wire format

A whole number, optionally signed. Leading zeros are legal on the wire and are preserved in the raw value. @boarteam/fix parses the value as a number and reports parse/invalid-int when it does not lex as one; the raw string is kept either way.

Read tag 538 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[538];field?.name;   // "NestedPartyRole"field?.raw;    // the verbatim wire stringfield?.value;  // coerced to a number

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