Hypothetical Iowa Unitary Business Taxable Income Computation
This is an example of how Iowa taxation might look if Iowa adopts a "combined reporting" system for C corporations.  This example is based on California's rules.
Iowa Sales Total Sales Taxable Income Iowa Factor Unitary %
Desmoinesco  $        10,000  $       1,000,000  $         100,000 1.00% 20.00%
Siouxfalls 1,000,000 4,000,000 400,000 25.00% 80.00%
Combined  $   1,010,000  $       5,000,000  $         500,000 20.20%
Iowa Taxable Income, Current Rules
Desmoinesco Income  $      100,000
Desmoinesco Iowa  factor 1.00%
Income allocable to Iowa  $          1,000
Iowa Taxable Income on Combined Basis
Combined income  $      500,000
Desmoinesco Iowa  factor (1) 1.00%
Income allocable to Iowa  $          5,000
(1) Because Siouxfalls is not taxable in Iowa, its factor is ignored in this computation.
Desmoinesco and Siouxfalls are corporations under common ownership operating as a unitary business.  Desmoinesco has Iowa nexus and is taxable in Iowa.  Siouxfalls has no Iowa nexus or oprerations; it only sells into Iowa from out of state. It is not taxable in Iowa