Property owners wishing to prohibit concealed firearms from being carried on their property must post officially approved signage conspicuously at the entrance of their building, premises or real property, according to a regulation published by the Illinois State Police. Owners of parcels where concealed carry is prohibited by the Illinois Firearms Concealed Carry Act also must post the required sign in the same manner. The IL state police have released guidance on the posting requirements as well as a model poster. For more information please review the details below.