When you sell your business, you may need to report all or part of the sale on your excise tax return. Also, you may be required to collect retail sales tax.The following items (tangible personal property) are subject to sales tax: Capital assets such as machinery and equipment, office furniture, and vehicles. In Washington State, personal property refers to assets used in conducting a business, other than real estate. Personal property tax is due April 30th. This publication explains the tax rules that apply when you dispose of property, including when you dispose of only a portion of certain property. All businesses in the state are responsible for filing a listing of their personal property each year with their county Assessor.