Idaho State Income Tax Overview

A portion of Idaho’s tax revenue comes from a personal income tax.  Personal income tax is assessed on Idaho residents and those who earn income of a source based in Idaho.  Those subject to Idaho personal income tax must file a tax return with the state of Idaho.  This is a separate tax return from that filed with the Internal Revenue Service (IRS) for federal income tax.

Following are frequently asked questions about Idaho state income taxes, including who has to file, filing dates, and tax rates.  If you are looking for additional information about federal income and tax returns, visit our “Tax Relief” page.

Who does Idaho require to file and pay personal income tax?

Residents

Residents are required to file a personal income tax return if they are required to file a federal income tax return and your gross income exceeds the amounts in the following table:

Status Gross Income
MARRIED:
Filing separate returns $3,700
Filing jointly, both spouses under 65 $19,000
Filing jointly, one spouse 65 or older $20,150
Filing jointly, both spouses 65 or older $21,300
HEAD OF HOUSEHOLD:
Under 65 $12,200
65 or older $13,650
SINGLE:
Under 65 $9,500
65 or older $10,950
QUALIFYING WIDOW(ER) WITH DEPENDENT CHILD:
Under 65 $15,300
65 or older $16,450

Part-Year/Non-Residents

Part-year/non-residents are required to file a personal income tax return if their gross income from all sources while a resident and from Idaho sources while a non-resident total more than $2,500.

Non-residents are required to file an income tax return if their gross income from all Idaho sources totals more than $2,500.

What tax rate does Idaho use for calculating personal income tax?

Idaho personal income tax is based on rates noted in the table below:

Single

At Least Less Than Tax Rate  

$1

$1,380

$.00

plus 1.6% of the amount over

$0

$1,380

$2,760

$22.08

plus 3.6% of the amount over

$1,380

$2,760

$4,140

$71.76

plus 4.1% of the amount over

$2,760

$4,140

$5,520

$128.34

plus 5.1% of the amount over

$4,140

$5,520

$6,900

$198.72

plus 6.1% of the amount over

$5,520

$6,900

$10,350

$282.90

plus 7.1% of the amount over

$6,900

$10,350

$527.85

plus 7.4% of the amount over

$10,350

Married

At Least Less Than Tax Rate  

$1

$2,760

$.00

plus 1.6% of the amount over

$0

$2,760

$5,520

$44.16

plus 3.6% of the amount over

$2,760

$5,520

$8,280

$143.52

plus 4.1% of the amount over

$5,520

$8,280

$11,040

$256.68

plus 5.1% of the amount over

$8,280

$11,040

$13,800

$397.44

plus 6.1% of the amount over

$11,040

$13,800

$20,700

$565.80

plus 7.1% of the amount over

$13,800

$20,700

$1,055.70

plus 7.4% of the amount over

$20,700

When is my Idaho personal income tax return due?

Idaho personal income tax is due on the first April 15 following the close of the tax year.  When April 15 falls on a holiday or weekend, your personal income tax return is due on the first business day thereafter.

You can obtain an automatic six-month extension on your time to file your Idaho personal income tax return if at least 80% of your tax liability for the year has already been withheld and you file your personal income tax return by October 15.  You will be charged interest on any unpaid tax liability not paid until after April 15.

What if I need help to calculate and file my Idaho personal income tax return?

By calling the telephone number at the top of this page, you can speak with a tax attorney who knows Idaho tax laws.  He will be able to assist you with completion both your state and federal income tax returns.

by Mark Johnston

Mark has been a contributor to legal web sites related to bankruptcy, tax, and criminal law since 2011. He has an Accounting degree from Texas A&M University.