Apportionment for tax years beginning prior to January 1, 2009.
Regulation 39-22-303.1. 
For income tax years beginning prior to January 1, 2009, every corporation doing business in Colorado and one or more other states has an annual election to apportion income under the provisions of section 39-22-303, C.R.S. (the Colorado Income Tax Act) or under the provisions of section 24-60-1301, C.R.S. (the Multistate Tax Compact). The election must be made with the filing of the Colorado income tax return and cannot be changed after the due date of the return.  Statutory references in this regulation refer to those sections as they existed prior to January 1, 2009.

Regulation 39-22-303.3.
(1) 	The provisions of this regulation apply for income tax years beginning prior to January 1, 2009.  Statutory sections referenced in the regulation refer to those sections as they existed prior to January 1, 2009.
(2) 	Inclusion of intangible drilling costs in the property factor. Intangible drilling costs should be included in both the numerator and the denominator of the property factor as computed under section 39-22-303(3), C.R.S. Since intangible drilling costs represent long range investments in the hope of producing oil or gas income, they are properly includable in the computation of the property factor. 
(3)	"Safe Harbor" lease property. "Safe Harbor" lease property shall be included in the property factor of the lessee/user and shall be excluded from the property factor of the lessor/owner.

Regulation 39-22-303.4.
(1) 	The provisions of this regulation apply for income tax years beginning prior to January 1, 2009.  Statutory sections referenced in the regulation refer to those sections as they existed prior to January 1, 2009.
(2)	"Safe Harbor" lease income. All income and deductions created by "safe harbor" lease transactions shall be included in the numerator of the Colorado revenue factor only if the lessor's commercial domicile is located in Colorado. All income and deductions created by "safe harbor" lease transactions shall not be included in the numerator of the Colorado revenue factor if the lessor's commercial domicile is not in Colorado. 
(3)	Colorado destination sales of a corporation not having nexus in Colorado when such corporation is an includable member of an affiliated group of corporations.  In the case of a corporation that does not have nexus (is not doing business) in Colorado even though it is an "includable corporation" in an affiliated group of unitary corporations filing a combined Colorado return, the sales of such corporation of property delivered to purchasers in Colorado shall not constitute Colorado sales for purposes of determining the revenue factor.

Regulation 39-22-303.10 
"Foreign source income" is taxable income from sources outside the United States as defined in section 862 of the internal revenue code. "Foreign source income" includes, but is not limited to, interest, dividends (including Sec. 78 "gross-up,") compensation for personal services, rents and royalties, and net income from the sale of property. "Foreign source income" is gross income, less expenses, losses, and other deductions properly apportioned or allocated thereto and a ratable part of any other expenses, losses, or deductions that cannot be allocated to some item or class of gross income.
IRC Sec. 78 dividend shall be subtracted from federal taxable income in accordance with 39-22-304(3)(j), C.R.S.
(1) 	If a taxpayer elects to claim foreign income taxes as a deduction for federal income tax purposes, such deductions shall also be allowed for Colorado income tax purposes.
	Colorado modifications to federal taxable income shall include any foreign source income and related foreign income taxes included in a combined report but not included in the federal return.
(2)	(a)  If a federal election is made to claim foreign taxes as a credit, a percentage of foreign source income shall be excluded from Colorado income subject to apportionment and from the numerator and denominator of the sales factor. 
	For purposes of this regulation, foreign tax includes tax paid or accrued, deemed paid, or carried over or carried back to the tax year, per the federal income tax return. Not included are taxes carried over from, or carried back to, a tax year beginning before Jan. 1, 1986.
The foreign source income exclusion shall be the lesser of:
(i) 	Foreign source income (Excluding Sec. 78 Dividend), or
(ii) 	The product of Foreign Taxes Paid (“FT”) and the Foreign Source Income (Excluding Sec. 78 Dividend) (“FSI net §78”) divided by the product of the effective federal corporation tax rate (“Fed Rate”) and the Foreign Source Income (Including Sec.78 Dividend) (“FSI”).  This is expressed as the following formula:
	(FT X “FSI net §78”) / (Fed Rate X FSI)
	The effective federal corporation tax rate means the combined taxpayer's federal corporate income tax (calculated in accordance with section 11(a) and (b) of the internal revenue code for such tax year) divided by the combined taxpayer's federal taxable income. As a formula:
	Effective federal corporate tax rate = federal corporate income tax / federal corporate taxable income 
	Modifications computed per this regulation shall be claimed as "other" additions or subtractions in the modification section of the Colorado corporate income tax return.
 (b) 	For tax years commencing prior to January 1, 2000, the denominator of the formula in subsection (b)(i) will use 46% in place of the effective federal corporation tax rate. 
(3) 	When determining foreign source income for a foreign corporation, such income shall not include any income of the foreign corporation that is derived from the conduct of a trade or business within the United States.
(4) 	For income tax years beginning on or after January 1, 2009, the excess, if any, of a taxpayer’s foreign source income over the foreign source income exclusion shall not be included in the numerator of the Colorado sales factor (see 39-22-303.5(4)(e)).

Apportionment of income on a combined report.
Regulation 39-22-303.11(c). 
(1) 	The provisions of this regulation apply for income tax years beginning on or after January 1, 2009.  The provisions of Regulation 39-22-303-11(c), as it existed prior to January 1, 2009, apply to income tax years beginning prior to January 1, 2009.
(2)	Except as otherwise provided in regulation 39-22-303-11(e), when filing a combined report, the affiliated group of corporations shall file one return, apportioning income under the provisions of either 39-22-303.5 C.R.S. or 39-22-303.7 C.R.S., summing the numerators to derive a single factor for the combined group.
Example: Of the unitary affiliated group of C corporations, A, B, and C, A and B are doing business in Colorado, C is not. The Colorado sales factors of the three corporations are as follows:
Corporation A:	Colorado sales	$5,160,118	
	Total sales	$7,652,492	
Corporation B:	Colorado sales	$ 183,290	
	Total sales	$ 314,005	
Corporation C:	Colorado sales	$1,642,720	
	Total sales	$80,009,652	
The combined sales factor would be as follows:
	Colorado sales (A+B) $5,343,408 = 6.0737%
Total sales  (A+B+C) $87,976,149*
* assuming no intercompany eliminations 
	The 6.0737% sales factor is applied to the combined modified federal taxable income (after intercompany eliminations) of the affiliated group to determine the Colorado taxable income to be reported on the combined filing.
(3)	A taxpayer may be engaged in activities that subject the taxpayer to more than one apportionment methodology; those activities may be engaged in by the same corporation or more than one corporation.  In these cases, the factors of the lines of business may bear no logical relationship to each other and the calculation of Colorado net income shall be done according to the sales provisions of Special Regulations for Allocation and Apportionment of Corporate Income 1-7.

Regulation 39-22-303.11(d). Refer to Regulation 39-22-305