NewSeqNo (FIX tag 36)

SeqNumFIX 4.4FIX 4.2

NewSeqNo (tag 36) is a SeqNum field defined in FIX 4.4 and FIX 4.2. It appears in 1 message type and is required in 1 of them.

At a glance

Tag
36
Name
NewSeqNo
Datatype
SeqNum (int)
Dialects
FIX 4.4 and FIX 4.2
Messages
1

What the specification says

New sequence number

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

A real message using tag 36

SequenceReset · FIX 4.4
TagFieldWire valueMeaning
8BeginStringFIX.4.4
9BodyLength68
35MsgType4Sequence Reset
49SenderCompIDBOARTEAM
56TargetCompIDCOUNTERPARTY
34MsgSeqNum2
52SendingTime20240101-12:00:00.000
36NewSeqNo1
10CheckSum143
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 36 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.

MessageMsgTypeFIX 4.4FIX 4.2Where in the message
SequenceReset4RequiredRequireddirectly on the message body

Wire format

A positive sequence number. Session-level, and monotonic within a session. @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 36 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[36];field?.name;   // "NewSeqNo"field?.raw;    // the verbatim wire stringfield?.value;  // coerced to a number

Other SeqNum fields

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