Business Message Reject <j> - Buildmarkets

Overview

The Business Message Reject message (MsgType = "j") is sent by the gateway when an application-level message cannot be processed. It differs from a Session Reject because the message has valid FIX structure but fails for business reasons.

Field Layout

Tag	Field	Description	Required	Type	Values
11	ClOrdID	Client’s order identifier from the rejected message	Y	String
37	OrderId	OrderId assigned by the gateway	Y	String
58	Text	Human-readable rejection reason	N	String
380	BusinessRejectReason	Rejection reason code	N	String

Example Message

8=FIX.4.4|35=j|49=BUILDMARKETS|56=CLIENT1|11=ORD-20260212-010|37=BMKT-78470|380=5|58=Insufficient buying power for order|10=023|

Handling Business Rejects

Examine Tag 58 (Text) for specific rejection details
Review Tag 380 for coded rejection reasons
The rejected order was not created — resolve the issue and resubmit
Common causes: insufficient buying power, disabled options trading, invalid symbols, or unauthorized security types

REST Equivalent

The REST API responds with HTTP 4xx errors containing JSON error details when order validation fails.