I am an Alaska resident who earns income in AK and ID. I filed as a non-resident for my ID tax. Why did my W-2 from my Alaskan employer affect my Idaho State Tax Return?

[JotikaT2]

It depends.

Idaho only taxes nonresidents on income that is generated from Idaho sources. Please see the following link for more information on what is considered Idaho source income.

What is considered Idaho source income

Your wages from Alaska should not impact your Idaho nonresident state tax return.  I would recommend reviewing the input on your W-2 wages from your employer in Alaska.  Make sure that the state input section does not show Idaho as the state source.

You can find this input as follows in the federal interview section.

1. Go to Income & Expenses 
2. Go to Wages 
3. Select Edit to the right of each W-2 form. 
4. Scroll down to box 15.  Review your input to ensure each W-2 is allocated to the correct state.

[SteamTrain]

Yeah

....your total Federal income does affect your ID Nonresident tax return.  Since your AK income is a part of that, then it will affect your ID taxation.

Briefly, they use the ratio (or %) of ID/Fed income to determine what amount of Itemized or Std deduction to apply to your Nonresident ID tax return.   There's some math handwaving and adjustments they make, but the gory details are  shown in lines 28-42 of the IDaho form 43  ... but TTX supposedly fills the proper amounts in for you once you go carefully thru all the ID nonresident Interview questions in the software.  BUT, you have to have the Federal section filled in first...every scrap.. before tackling the actual ID nonresident interview..

https://tax.idaho.gov/forms/EFO00091_12-03-2020.pdf