Taxpayers having cross-border operations are confronted with numerous tax information forms to be filed as part of the annual tax return.  Because the forms are not directly used to compute taxable income, they frequently are completed at the last minute and with less attention to detail.  However, the I.R.S. imposes penalties for filing an incomplete form.  Taxpayers faced with asserted penalties often argue that the forms are substantially complete.  In a recent International Practice Unit (“I.P.U.”) issued by the Large Business & International Division of the I.R.S., the I.R.S. view regarding substantially complete form was explained.  Not surprisingly, the I.R.S. view is significantly different from taxpayer expectations.  It also differs from holdings in several Tax Court decisions involving other forms.  Neha Rastogi and Stanley C. Ruchelman discuss the I.P.U. in detail.