Insurer ID (W Number)

Insurers and employers who have been approved to self-insure for workers’ compensation benefits in New York State are assigned a 7-character identification number beginning with a W (known as a “W Number” or “Insurer Code (ID) Number”) by the Workers’ Compensation Board. This number is used to identify workers’ compensation coverage in the Board’s insurance coverage system and to gain access to electronic case files for workers’ compensation claims (eCase) and filing of required documentation.