Should I file as part year resident filing as a resident or part year resident filing as a nonresident?

[sonky7]

I moved to MO in August 2018 from a home and job in Illinois to start my job in MO and live in MO. It says that if I chose part year resident that it'll tax my entire 2018 income of already taxed IL income.  While it says if I chose resident that I'll receive "credit" for my already paid taxes, I have yet to see any fluctuation or application of said credit. It seems that if I chose resident then I'll get double taxed by two high taxing states on my already small amount of earning. 

[KatrinaB]

Since you were a resident of each state during 2018 then you need to file a part-year resident return for each state. You will also allocate your income between the two states. Please view the directions for doing so in the TurboTax FAQ below.

https://ttlc.intuit.com/replies/4777389