Indiana's flat tax rate and who pays it

Indiana has a flat income tax rate of 3.15 percent on wages, salaries, and most other income. This rate applies to all Indiana residents and to anyone earning income within the state, regardless of how much they make. Unlike some states that use brackets where higher earners pay higher rates, Indiana taxes everyone at the same percentage.

The 3.15 percent rate has been in place since 2022. Before that, Indiana used a graduated system with rates ranging from 3.27 percent to 5.75 percent depending on income level. The shift to a flat tax simplified the calculation but did not change the fact that Indiana collects income tax on most forms of earned and unearned income.

Key Takeaways

  • Indiana's state income tax rate is 3.15 percent, applied equally to all residents and income earners in the state.
  • The tax applies to wages, salaries, interest, dividends, capital gains, and most other income sources, though some types of income are excluded.
  • Indiana allows a standard deduction that reduces the income amount subject to tax, and the amount depends on your filing status.
  • You must file an Indiana tax return if you earned income in the state and owe tax, even if you also file a federal return.
  • Retirement income, including Social Security and some pension payments, receives special treatment and may not be fully taxed.

What income is subject to Indiana tax

Indiana taxes wages and salaries, self-employment income, interest, dividends, capital gains, rental income, and income from partnerships and S corporations. If you earned money in Indiana or are an Indiana resident, you generally owe tax on that income at the 3.15 percent rate.

Some income is excluded from Indiana taxation. Social Security benefits are not taxed by Indiana. Certain pension and retirement distributions also receive preferential treatment — Indiana allows a deduction for some retirement income, which means part or all of it may not be subject to the 3.15 percent tax. The rules for retirement income are complex and depend on the source and your age, so reviewing your specific situation with a tax preparer or the Indiana Department of Revenue is worth the time if you receive pensions or retirement distributions.

Standard deduction and filing requirements

Indiana allows a standard deduction that reduces the amount of your income subject to tax. For the 2024 tax year, the standard deduction is $6,950 for single filers and $13,900 for married couples filing jointly. These amounts are adjusted each year for inflation, so check the Indiana Department of Revenue website for the current year's amounts.

You must file an Indiana return if you earned income in the state and your income exceeds the standard deduction for your filing status. Even if you do not owe Indiana tax, you may need to file if you had tax withheld from your paychecks — filing allows you to claim a refund of that overpayment. Indiana residents who work out of state may also have filing obligations depending on where they earned income and what taxes were withheld.

How withholding works on your paycheck

If you work in Indiana, your employer withholds Indiana income tax from your paycheck based on the W-4 form you complete. The withholding is calculated using your gross pay, filing status, and the number of allowances you claim. The amount withheld is sent to the Indiana Department of Revenue on your behalf.

If too much tax is withheld during the year, you receive a refund when you file your return. If too little is withheld, you owe the difference. You can adjust your withholding by submitting a new W-4 to your employer if your circumstances change — for example, if you get married, have a child, or take a second job. The Indiana Department of Revenue website has a withholding calculator to help you determine whether your current withholding is correct.

Self-employed and business income

If you are self-employed or own a business in Indiana, you owe the 3.15 percent state income tax on your net business income. You calculate net income by subtracting business expenses from gross revenue. You also owe federal self-employment tax, which funds Social Security and Medicare, but that is separate from Indiana state income tax.

Self-employed people do not have an employer to withhold tax, so you may need to make quarterly estimated tax payments to Indiana to avoid owing a large amount when you file your return. The Indiana Department of Revenue provides forms and instructions for calculating and paying estimated tax. Keeping detailed records of income and expenses throughout the year makes calculating your tax liability much simpler when tax time arrives.

Tax credits and deductions available in Indiana

Indiana offers several tax credits that can reduce the amount of tax you owe. The Earned Income Tax Credit (EITC) is available to low- and moderate-income workers and is calculated based on your federal EITC. Indiana also offers credits for child and dependent care expenses, education expenses, and property taxes paid.

Beyond the standard deduction, Indiana allows deductions for charitable contributions, mortgage interest, and certain other expenses if you itemize rather than take the standard deduction. However, most Indiana taxpayers benefit more from the standard deduction than from itemizing. The Indiana Department of Revenue publishes a guide each year listing all available credits and deductions, which is useful if your situation is complex.

Filing your Indiana return

Indiana residents file their state return using Form IT-40 or IT-40PNR (for part-year residents). You can file online through the Indiana Department of Revenue website, by mail, or through a tax preparation service. The filing important date is the same as the federal important date — typically April 15 of the year following the tax year, though the date shifts if April 15 falls on a weekend or holiday.

If you cannot file by the important date, you can request an extension, which gives you until October 15 to file. An extension to file is not an extension to pay — if you owe tax, it is due by the original April important date even if you file late. Paying what you estimate you owe by April 15 avoids penalties and interest on the unpaid balance.

Frequently Asked Questions

Do I have to pay Indiana income tax if I live in another state but work in Indiana?

Yes, Indiana taxes income earned within the state regardless of where you live. However, you may also owe tax to your home state on the same income. Most states have reciprocal agreements or credits to prevent double taxation, so you typically pay tax to one state or the other, not both. Contact both state tax agencies or a tax preparer to understand your specific situation.

Is Social Security taxed in Indiana?

No, Indiana does not tax Social Security benefits. However, if you have other income above certain thresholds, some of your Social Security may be taxed at the federal level. Indiana's exemption applies only to the state tax.

What happens if I do not file an Indiana return?

If you owe tax and do not file, the Indiana Department of Revenue can assess penalties and interest on the unpaid amount. If you had tax withheld and do not file, you straightforward do not receive your refund. Filing is worth doing even if you do not owe, because it ensures you get back any overpaid tax.

Can I file my Indiana return electronically?

Yes, the Indiana Department of Revenue encourages electronic filing through its website or through a tax preparation software or preparer. E-filing is faster than mailing a paper return and provides confirmation that your return was received.

What is the penalty for filing late?

Indiana charges a failure-to-file penalty of 5 percent per month (up to 25 percent total) of the unpaid tax if you file late. A failure-to-pay penalty of 0.5 percent per month also applies to unpaid tax. These penalties are reduced or waived if you have reasonable cause for the delay, so contact the Indiana Department of Revenue if you have a legitimate reason for filing late.