My return says I owe $107 in additional tax code UT. what is this?

[CherylW · Accepted solution]

UT=Unpaid Tax.

It could be

1.  a retirement benefit that's taxable to you,

2.  unpaid FICA tax if you're a waitperson.

You'll have either a A, B, M, or N code in box 12 of your W-2.