Nebraska Personal Property Return must be filed with the County Assessor on or before May 1. County Assessor address and contact information.Search and select the business and then click on "Datasheet. The top portion of the listing form is for basic information about your business. This tax is imposed on the retail purchase of tangible personal property titled or registered with the State of Illinois to an address located in Cook County. This return must be filed on or before May 1st in the office of the County Assessor where the personal property is located. Personal property must be reported annually to the county assessor and is based on the depreciated life of an asset. Portal for filling out and submitting Business Personal Property Listings and Extensions. Taxscribe tutorial . Property held but taxable to others, shall be listed in the name of the owner on Schedule 7.