A few comments on your follow-up response:
- You don't indicate what return you filed for Missouri. Did you file a nonresident tax return?
- When you completed your MO return, did you indicate that you had zero MO income?
- Has your employer corrected their withholding of MO tax?
- Is there an address on the letter you received?
*A reminder that posts in a forum such as this do not constitute tax advice.
Also keep in mind the date of replies, as tax law changes.
