What is state income tax?

State income tax is a tax that individual US states levy on the earned income of workers employed within their borders.

Employers act as withholding agents by deducting the applicable amount from each employee's paycheck and remitting it to the state's revenue authority on the employee's behalf.

Unlike federal income tax, which applies uniformly across the country, state income tax varies significantly in rate, structure, and rules. Some states use a flat rate, others use progressive brackets, and a handful levy no income tax on earned wages at all.

How state income tax works

State income tax applies to wages and salaries earned within a state's jurisdiction. The employee bears the tax liability, and the state's revenue authority determines the applicable rate, brackets, and filing requirements. Employees reconcile any overpayment or underpayment when they file their annual state tax return.

Employers do not pay state income tax themselves but are responsible for calculating and withholding the correct amount each pay period. The withheld funds flow from the employer to the state authority on a schedule that authority sets, usually monthly or quarterly.

State income tax withholding for employers

Before running payroll in any state with an income tax, an employer must register with that state's tax authority. The employer establishes the account from which they file returns and remit withheld amounts. An employer that does not register before the first payroll commits a compliance violation in most states.

Withholding depends on information the employee provides, such as filing status and allowances, typically on a state-specific withholding certificate. The employer uses that information alongside the state's withholding tables to determine the correct payroll deductions each period. Each pay period's deduction appears on the employee's pay stub.

Employers report total state wages withheld for the year on Form W-2, which employees use to file their federal and state returns. Our state payroll tax guide outlines the payroll tax requirements for each state.

States without state income tax

Nine states do not levy income tax on earned employment wages: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming. Employers with workers in those states still have federal and other employer payroll tax obligations but face no state income tax registration or withholding requirement for those locations.

Whether a state requires withholding is a foundational part of ongoing payroll compliance for any company with a distributed US workforce. See state income tax rates outlined in our guide.

State income tax and multi-state employees

When an employee performs work in more than one state, multiple states may assert the right to tax those wages. The rules for sourcing wages across states vary, and not every employer-employee situation resolves neatly to a single state. Employers managing multi-state payroll encounter complexity that requires state-specific expertise.

Reciprocal state agreements between neighboring states can simplify some situations. Under a reciprocal agreement, an employee who lives in one state and works in another typically pays income tax only to their home state, which reduces the employer's withholding complexity. Not every pair of states has such an agreement, so employers must verify coverage before applying a single-state approach.

Key facts

• Employee liability and employer withholding: The employee owes state income tax on their wages, and the employer withholds and remits the correct amount to the state authority on their behalf.

• Rates and structures vary: States may use flat rates or progressive brackets, and the amount withheld depends on the employee's filing status and elections.

• Registration before the first payroll: Employers must register with a state's tax authority before running payroll in that state.

• Nine states do not have state income tax: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming do not tax earned employment income.

• Multi-state workers add complexity: When an employee works across state lines, the employer may need to withhold for more than one state, depending on each state's rules and any applicable reciprocal agreements.

• Annual reconciliation via Form W-2: Employers report total state wages withheld each year on Form W-2, which employees use to file their state returns.

Managing state income tax compliance with Deel Payroll (US)

State income tax compliance across multiple states is one of the most common ongoing challenges US employers face. Deel Payroll (US) is built to handle federal, state, and local payroll tax requirements accurately and on time, so companies don't have to track rate changes and registration deadlines manually.

We handle state income tax withholding calculations, remittances, and filings while giving teams the flexibility to run payroll independently or with expert support from our team. The platform integrates with HR, 401(k), and benefits administration so the data flows consistently across your workforce. Manage and pay all your US employees in one scalable system with Deel Payroll (US).

FAQ

Is state income tax the same as federal income tax?

No. The US federal government levies federal income tax on income earned anywhere in the country under a single set of brackets, while each state levies its own tax on income earned within its borders. An employer must calculate and remit both independently.

Do remote workers pay state income tax?

The state where an employee physically performs their work generally has the right to tax those wages. If a remote worker lives and works in a different state from their employer's location, the employee's home state typically applies. Some pairs of states have reciprocal agreements that limit double-withholding obligations, so employers must verify the rules for each state where their workforce is located.

What happens if an employer withholds the wrong state income tax amount?

Incorrect or missing withholding can result in penalties and interest from the state tax authority. The employee remains responsible for any unpaid tax on their return, and the employer may face its own compliance consequences for under-remitting. Accurate registration, correct withholding calculations, and timely remittances are the core obligations to meet.

Can an employee avoid state income tax by working from a no-income-tax state?

An employee based in a state that levies no income tax on earned wages does not owe that state's income tax. If the employee's state of legal residence taxes income, however, that state may still have a claim. Tax residency rules vary by state, and employees should consult qualified tax advisers about their specific situation.

This article is for informational purposes only and is not legal or tax advice, so employers should consult qualified tax advisers for guidance on their specific state income tax withholding obligations.