Did (1) you move from one state to the other during 2020, or (2) are you filing a Nonresident ("NR") return in one state, and a Resident ("R") one in the other? If so, which is NR and which is R?
NR California, full time resident UT. We move to UT in 2012 and have not lived in CA since then.
The Utah tax form (TC-40) starts with federal income because of the way Utah calculates tax on part-year residents. However you are not being tax on federal income; only the UT percentage.
Utah first calculates a base tax rate as if all your income were earned in Utah. Your actual tax is the Utah income percentage of the base tax. For example, if you earned $159,915 total and $73,300 in UT, your Utah tax would be the UT tax on $159,915 x ($73,300/$159,915),
The tax computation is shown on Form TC-40B.