Provides necessary revenue for the support of vital state services on a more stable and equitable basis.

Imposes a tax on all taxable income of resident individuals, estates, and trusts and on all individuals, estates, and trusts deriving income from sources in Washington for each taxable year based on the type of return filed and the amount of income.

Provides that the act takes effect only if the proposed amendment to Article VII of the state Constitution authorizing income taxes is approved by the voters at a general election held in November 2010.