Partnerships that have effectively connected taxable income (ECTI) allocable to foreign partners use this schedule to determine: Whether they are subject to the penalty for underpayment of estimated tax and, if so, The amount of the underpayment penalty. Current Revision Schedule A (Form 8804) PDF Instructions for Schedule A (Form 8804) PDF (HTML) Recent Developments Other Items You May Find Useful All Schedule A (Form 8804) Revisions Other Current Products Related About Form 8804, Annual Return for Partnership Withholding Tax (Section 1446)