Definition of business income and the business income base

# (a)

Business income is entire net income minus other exempt income and investment income. It also includes:

# (1)

interest deductions directly or indirectly attributable to gross investment income or investment capital that exceed the amount of gross investment income; and

# (2)

interest deductions directly or indirectly attributable to gross other exempt income that exceed the amount of gross other exempt income.

# (b)

Total business income is the sum of business income and income from presumed investment capital from the immediately preceding tax year required to be added back pursuant to section 3-4.4(a)(2) of this Part.

# (c)

# (1)

The business income base is equal to:
(i) the product of total business income and the business apportionment factor determined under this Subchapter; minus
(ii) the prior net operating loss conversion subtraction and the net operating loss deduction.

# (2)

In computing total business income of the combined group, all intercorporate dividends between corporations included in the combined report must be eliminated and all other intercorporate transactions between corporations included in the combined report must be deferred in a manner similar to the United States treasury regulations relating to intercompany transactions under IRC section 1502.