The Washington Department of Revenue has provided interim guidance on the application of business and occupation (B&O) tax to collective investment vehicles (CIV). The department will treat investment income of a CIV as nontaxable. Amounts received by a CIV from non-investment sources are taxable. Also, amounts received by investors in a CIV are taxable, unless a deduction or exemption applies to such investors or unless the investors are considered to not be engaging in business in regards to the investment activity. A CIV may take the form of a mutual fund, collective fund, or similar investment vehicle. Interim Guidance Statement Regarding Collective Investment Vehicles and Investment Income, Washington Department of Revenue, April 16, 2025