Most states levy an income tax on their residents that is in addition to the federal income tax. Laws vary from state to state but in most states the state income tax is a tax on the annual earnings of individuals, corporations, trusts, limited liability companies, and other legal entities.
There are nine states that do not have a state income tax—including Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming. But New Hampshire levies a tax on capital gains and Washington state recently enacted a tax on extraordinary profits from the sale of financial assets over $250,000.
In Connecticut (CT), residents are subject to state income tax in addition to the federal income tax. The state income tax in Connecticut applies to the annual earnings of individuals, corporations, trusts, limited liability companies, and other legal entities. The tax rates and brackets for individuals are progressive, meaning that the rate increases as income rises. Connecticut also imposes a corporate income tax, with rates that vary depending on the corporation's income level. Unlike the nine states mentioned that do not have a state income tax, Connecticut does levy such a tax on its residents and businesses. It's important for residents and entities in Connecticut to be aware of their tax obligations and to file their state income tax returns annually by the appropriate deadline.