Hi,
Last year(2009 taxrefund) I used turbotax; however this year(2010 tax refund) I understand that I have to fill the 1040-NR and I used CINTAX. There is a question on CINTAX that "what form did I fill last year". I want to tell IRS that I filled the wrong form. Would you please let me know how should I answer the question, because I want to tell them voluntarily and I do not want to pay the penalty.
In addition, would you please let me know which documents I have to send for amending.
Thanks,
BA

No at all