NestedPartySubID (FIX tag 545)

StringFIX 4.4FIX 5.0 SP2

NestedPartySubID (tag 545) is a String field defined in FIX 4.4 and FIX 5.0 SP2. It appears in 22 message types, always optionally.

At a glance

Tag: 545
Name: NestedPartySubID
Datatype: String
Dialects: FIX 4.4 and FIX 5.0 SP2
Messages: 22

What the specification says

FIX 4.4

PartySubID value within a nested repeating group. Same values as PartySubID (523)

FIX 5.0 SP2

PartySubID 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 545

NewOrderSingle · FIX 4.4

Tag	Field	Wire value	Meaning
8	BeginString	FIX.4.4
9	BodyLength	175
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	NoNestedPartyIDs1 entry	1	repeating group
524	NestedPartyID	EXAMPLE
804	NoNestedPartySubIDs2 entries	2	repeating group
545	NestedPartySubID	EXAMPLE
545	NestedPartySubID	EXAMPLE
54	Side	1	Buy
60	TransactTime	20240101-12:00:00.000
40	OrdType	1	Market
10	CheckSum	099

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

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 545 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[545];field?.name;   // "NestedPartySubID"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