Access forms available from the Assessor's office, including benefits, business personal property, change in ownership, and other general forms. Forms ; CH-800, Proof of Firearms Turned In, Sold, or Stored ; CH-800-INFO, How Do I Turn In, Sell, or Store My Firearms?The guide is divided into eight sections – (I) Overview for. Filing a Business Property Statement, (II) Filing a Form 571-L Electronically (e-File),. The below link will take you directly to the Assessor's Office forms page. The PCOR is near the bottom of the page under "Change in Ownership Forms". Who must file a Business Property Statement (BPS)? Everything you need to know about Contra Costa Property Tax, including rates, laws, and ways to reduce your bills. Get help with utility bills and other types of bill assistance. Low-income and Medical Baseline assistance.