Hard to say for sure, but a common penalty is not withholding enough throughout the year. The rules are a little complicated and I don't know anything about CO ...
If those two numbers you mentioned - $4400 and $3585 - represent the amount she gets or pays as of April 15th, and not her total tax, then I would look closely ...
As you've described it, you made a payment before you efiled. Then you tried to efile and were rejected because your ssn had already been used to efile.It reall...
