Clarifying the business and occupation tax treatment of the investment income of passive investment vehicles managed by a person subject to business and occupation tax under RCW 82.04.290(1).

This bill clarifies which investment income qualifies for a business and occupation (B&O) tax deduction under Washington state law. It specifically addresses income from passive investment vehicles managed by entities already subject to B&O tax (as defined in RCW 82.04.290(1)), ensuring this income remains deductible. The amendment to RCW 82.04.4281 explicitly includes "amounts derived from investments made pursuant to an investment management or advisory agreement" under the deduction rules, while defining key terms like "investment" and excluding certain loan-related income. The change aims to resolve uncertainty caused by recent court decisions and provides retroactive application without creating refund rights for taxes paid before the law's effective date.