Idaho State Tax Commission

Changes to 2018 individual income tax form instructions

We’ve updated our 2018 individual income tax form instructions due to recent law changes. The updates apply to part-year residents and nonresidents who claim the child tax credit, married taxpayers filing separately, and those who are itemizing. For details, see below or read the highlighted yellow box on our individual income tax forms page. 

Instruction changes

Nonresident or part-year resident? Idaho part-year residents qualify for the Idaho child tax credit for the part of the year they were an Idaho resident; calculate using the four steps below. Nonresidents don't qualify. (Following passage of 2019 House Bill 19 on 02-13-2019)

  1. Determine the number of months you lived in Idaho (over 15 days counts as a month)
  2. Multiply line 1 by $17.08
  3. Multiply line 2 by the number of your qualifying children.
  4. Enter amount from line 3 on Form 43, line 45.

Married Filing Separately filing requirements — You must file a tax return if your gross income is at least $5. (Following update to IRS instructions, revision date 01-24-2019)

Itemizing? – If you use federal Schedule A to itemize, please note these additional instructions for Form 40, line 15 and Form 43, line 35.

  • If federal Schedule A, line 5d, is $10,000 or less ($5,000 if married filing separately), enter the amount from federal Schedule A, line 5a.
  • If federal Schedule A, line 5d, is more than $10,000 ($5,000 if married filing separately), subtract line 5b from line 5e and enter the amount here. Enter zero for any result less than zero.


Posted 03-13-2019
tax pros general

This information is for general guidance only. Tax laws are complex and change regularly. We can't cover every circumstance in our guides. This guidance may not apply to your situation. Please contact us with any questions. We work to provide current and accurate information. But some information could have technical inaccuracies or typographical errors. If there's a conflict between current tax law and this information, current tax law will govern.