Type: String
Unique identifier of execution message as assigned by broker (will be 0 (zero) for ExecTransType=3 (Status)).
Uniqueness must be guaranteed within a single trading day or the life of a multi-day order. Firms which accept multi-day orders should consider embedding a date within the ExecID (17) field to assure uniqueness across days.
(Prior to FIX 4.1 this field was of type int)
Added in protocol FIX.2.7
See in: FIX.4.0, FIX.4.1, FIX.4.2, FIX.4.4, FIX.5.0, FIX.5.0SP1, FIX.5.0SP2, FIX.5.0SP2 EP240.