Order Cancel Reject <9> - Buildmarkets

Overview

The Order Cancel Reject message (MsgType = "9") is sent by the gateway when a cancellation request cannot be processed. This typically occurs when an order is already filled, expired, or in a non-cancellable state.

Field Layout

Tag	Field	Description	Required	Type	Values
11	ClOrdID	Identifier of the cancel request	Y	String
17	ExecId	Execution ID assigned by the gateway	Y	String
37	OrderId	OrderId assigned by the gateway	Y	String
39	OrdStatus	Current order status	Y	Char	`8`=Rejected
41	OrigClOrdID	ClOrdID of the order that could not be cancelled	Y	String
58	Text	Reason for rejection (free text)	N	String
434	CxlRejResponseTo	Type of request being rejected	Y	Int	`1`=Order Cancel Request

Example Message

8=FIX.4.4|35=9|49=BUILDMARKETS|56=CLIENT1|11=CXL-20260212-001|17=EXEC-020|37=BMKT-78450|39=8|41=ORD-20260212-001|434=1|58=Order already filled|10=056|

Handling Cancel Rejects

Review Tag 58 (Text) for the human-readable rejection reason
The original order maintains its current state — use Order Status Request to verify if needed
Common rejection causes: order already filled, order already cancelled, order expired, or invalid OrderId

REST Equivalent

The REST cancel endpoint (POST /api/external/cancel) provides similar functionality, returning error details when cancellation fails.