How Utah withholds on a bonus
Utah withholds a separately paid bonus at its flat 4.5% rate; the state's withholding guide (Publication 14) has no separate supplemental figure because a flat tax does not need one. On a $10,000 bonus the percentage method withholds $2,200 federal, $620 Social Security, $145 Medicare and $450 Utah, leaving $6,585. There are no local income taxes in Utah.
Because the rate is flat, the aggregate method leaves Utah's line almost unchanged and raises the federal line to about $2,700 for a $60,000 earner paid every two weeks. Utah's taxpayer tax credit, which stands in for a standard deduction, has usually been fully used or phased out by regular salary, so a bonus is taxed at the full 4.5% on the return and the state withholding settles even.
What the withholding means for your Utah return
Any refund on a Utah bonus is federal: a $60,000 single filer's marginal federal rate is 12% up to $50,400 of taxable income and 22% above, so a $10,000 bonus is really taxed at about $1,450 federal against $2,200 withheld, and roughly $750 returns. Nevada and Wyoming residents who earn a bonus for work in Utah are withheld for Utah on it. The Utah paycheck calculator shows the marginal rates for any salary. Utah uses the federal W-4, whose entries do not change the flat 4.5% withheld from a separately paid bonus; they matter only under the aggregate method. Utah's rate has been cut in each of the last four sessions, and the bonus rate moves with it.