If you make a mistake on your return, that is not criminal.  However, filing a wilfully fraudulent return iscriminal and can land you in jail.  Here are some things you do not want to do that, if done, can lead to a criminal investigation: (1) failure to report all of your earned income; (2) failure to report all of your unearned income, such as investments, rent, etc.; (3) failure to report any money held in foreign banking institutions or invested overseas; (4) exaggerating deductions; (5) inflating self-employment expenses (now IRS computers compare deductions and expenses year to year and a spike can trigger an audit). Next week I will list five more “no-no” things that can cause trouble.