If you received a Notice to File a Business Property Statement from the Assessor and your business is no longer in operation, you are still required to file the Business Property Statement. You should also include a note on the Business Property Statement indicating that the business has closed, so the Assessor does not continue to assess the property.
In a few states, you must take an additional step to make your company official: You must publish a simple notice in a local newspaper, stating that you intend to form an LLC. You are required to publish the notice several times over a period of weeks and then submit an "affidavit of publication" to the LLC filing office. Your local newspaper should be able to help you with this filing.
You must report personal property holdings in detail and as requested or mandated. If nothing has changed from the prior year (no equipment was purchased or sold), then you may refer to your prior year's Business Property Statement filing in order to be consistent in completing the current Business Property Statement. If you failed to keep a copy of the prior year's filing, you may request a copy of it from the Assessor's Office.