Personal property tax is due on most property used in conducting business. If you choose to file using QuickFile, you can complete the entire process in a matter minutes!What is QuickFile and why is it beneficial? Instructions for completing the paper listing form are on the form itself and can also be accessed on the Skagit County Assessor website. In Washington State, the listing of business personal property is a self-reporting system. All businesses in Mason County are responsible for filing a personal property listing each year. When completing the form you must: 1. New businesses are required to complete a Personal Property Itemized Listing form. For a blank form, click here. Personal property in Washington is subject to property tax just like real property.