Washington Attachment for Residential Split Adjustment is a form used by Washington State homeowners to adjust their residential property tax assessments when their properties are split. This form is used when the owner has split their home into two or more residential properties, either for sale or rental, and the Tax Assessor has not yet identified the separate properties. The form is used to adjust the tax assessment for the separate properties and to ensure that the owner is not over-taxed. There are two types of Washington Attachment for Residential Split Adjustment: Primary Residential Attachment and Secondary Residential Attachment. The Primary Residential Attachment is used when two or more properties are split for sale or lease, and the tax assessment must be adjusted. The Secondary Residential Attachment is used when a property is split for rental purposes only, and the tax assessment must still be adjusted. Both forms must be completed and submitted to the Tax Assessor to finalize the adjustment.