Every partnership deriving income (1) from property owned within this state or (2) from a business, trade, profession or occupation carried on within the state must make a return of income regardless of the amount of income or loss and regardless of the residence of the partners. The return shall be made on the proper form and signed by one of the partners. The return shall be made on the same period basis, calendar or fiscal, as the partnership accounts are kept, irrespective of the fact the partners are reporting their incomes on a different period basis. The return shall be filed with the department on or before the last day of the fourth month after the expiration of the tax year
This rule is intended to implement Iowa Code section 42221..
Iowa Admin. Code r. 701-45.2