By law, most sellers of real property must provide a completed Seller Disclosure Statement (aka Form 17) to any buyer. Almost every home seller in WA must complete a Seller Disclosure Statement, aka the Form 17.Learn more, and get a copy you can use for free! Nearly all real estate sales in Washington State require a seller disclosure statement, also known as Form 17, to be given to the buyer. The Form 17 permits a seller to mark answers to the form questions as "Yes", "No", "I don't know", and "NA." Grades K–5 ; Scouts BSA. Complete ATTACHMENT A: PRICING FORM and upload in the Sourcing Tool. Check if this is an amended return. 10 Additional Regional State Sales and Use. See ST-8A Worksheet.