(a)(1) Every mutual savings bank, savings and loan association and every company engaged in the business of carrying passengers for hire over the highways of this state in common carrier motor vehicles doing business in this state, and every other company carrying on, or having the right to carry on, business in this state, including a dissolved corporation which continues to conduct business, except those companies described in subdivision (2) of this subsection, shall pay, annually, a tax or excise upon its franchise for the privilege of carrying on or doing business, owning or leasing property within the state in a corporate capacity or as an unincorporated association taxable as a corporation for federal income tax purposes or maintaining an office within the state, such tax to be measured by the entire net income as herein defined received by such corporation or association from business transacted within the state during the income year and to be assessed for each income year commencing prior to January 1, 1995, at the rate of eleven and one-half per cent, for income years commencing on or after January 1, 1995, and prior to January 1, 1996, at the rate of eleven and one-quarter per cent, for income years commencing on or after January 1, 1996, and prior to January 1, 1997, at the rate of ten and three-fourths per cent, for income years commencing on or after January 1, 1997, and prior to January 1, 1998, at the rate of ten and one-half per cent, for income years commencing on or after January 1, 1998, and prior to January 1, 1999, at the rate of nine and one-half per cent, for income years commencing on or after January 1, 1999, and prior to January 1, 2000, at the rate of eight and one-half per cent, and for income years commencing on or after January 1, 2000, at the rate of seven and one-half per cent. The exemption of companies described in subparagraphs (G) and (H) of subdivision (2) of this subsection shall not be allowed with respect to any income year of any such company commencing on or after January 1, 1998, and any such company claiming such exemption for any income years commencing on or after January 1, 1985, but prior to January 1, 1998, shall be required to file a corporation business tax return in accordance with section 12-222 for each such income year.
(2) The following companies shall be exempt from the tax imposed under this chapter: (A) Insurance companies incorporated or organized under the laws of any other state or foreign government and for income years commencing on or after January 1, 1999, domestic insurance companies; (B) companies exempt by the federal corporation net income tax law, and any company which qualifies as a domestic international sales corporation (DISC), as defined in Section 992 of the Internal Revenue Code and as to which a valid election under subsection (b) of said Section 992 to be treated as a DISC is effective, but excluding companies, other than any company which so qualifies as, and so elects to be treated as, a DISC, which elect not to be subject to such tax under any provision of said Internal Revenue Code other than said subsection (b) of Section 992; (C) companies subject to gross earnings taxes under chapter 210; (D) companies all of whose properties in this state are operated by companies subject to gross earnings taxes under chapter 210; (E) cooperative housing corporations, as defined for federal income tax purposes; (F) any organization or association of two or more persons established and operated for the exclusive purpose of promoting the success or defeat of any candidate for public office or of any political party or question or constitutional amendment to be voted upon at any state or national election or for any other political purpose; (G) any company which is not owned or controlled, directly or indirectly, by any other company, the gross annual revenues of which in the most recently completed year did not exceed one hundred million dollars and which engaged in the research, design, manufacture, sale or installation of alternative energy systems or motor vehicles powered in whole or in part by electricity, natural gas or solar energy including their parts and components, provided at least seventy-five per cent of the gross annual revenues of such company are derived from such research, design, manufacture, sale or installation; (H) any company which engages in the research, design, manufacture or sale in Connecticut of aero-derived gas turbine systems in advanced industrial applications, which applications are developed after October 1, 1992, which are limited to simple-cycle systems, humid air, steam or water injection, recuperation or intercooling technologies, including their parts and components, to the extent that such company's net income is directly attributable to such purposes; (I) any non-United States corporation, which shall be any foreign corporation, as defined in Section 7701(a)(5) of the Internal Revenue Code, whose sole activity in this state during the income year consists of the trading in stocks, securities or commodities for such corporation's own account, as defined in Section 864(b)(2)(A)(ii) of said Internal Revenue Code; and (J) for income years commencing on or after January 1, 2001, S corporations.
(3) (A) A company is carrying on or doing business in this state if it is a general partner of a partnership that does business, owns or leases property or maintains an office in this state. (B) A company is carrying on or doing business in this state if it is a limited partner of a limited partnership, other than an investment partnership, that does business, owns or leases property or maintains an office in this state. (C) A company that is not otherwise carrying on or doing business in this state, either directly or by virtue of being a partner in a partnership described in subparagraph (A) or (B) of this subdivision is not carrying on or doing business in this state solely by virtue of being a limited partner of one or more investment partnerships.
(b) (1) With respect to income years commencing on or after January 1, 1989, and prior to January 1, 1992, any company subject to the tax imposed in accordance with subsection (a) of this section shall pay, for each such income year, an additional tax in an amount equal to twenty per cent of the tax calculated under said subsection (a) for such income year, without reduction of the tax so calculated by the amount of any credit against such tax. The additional amount of tax determined under this subsection for any income year shall constitute a part of the tax imposed by the provisions of said subsection (a) and shall become due and be paid, collected and enforced as provided in this chapter.
(2) With respect to income years commencing on or after January 1, 1992, and prior to January 1, 1993, any company subject to the tax imposed in accordance with subsection (a) of this section shall pay, for each such income year, an additional tax in an amount equal to ten per cent of the tax calculated under said subsection (a) for such income year, without reduction of the tax so calculated by the amount of any credit against such tax. The additional amount of tax determined under this subsection for any income year shall constitute a part of the tax imposed by the provisions of said subsection (a) and shall become due and be paid, collected and enforced as provided in this chapter.
(3) With respect to income years commencing on or after January 1, 2003, and prior to January 1, 2004, any company subject to the tax imposed in accordance with subsection (a) of this section shall pay, for each such income year, an additional tax in an amount equal to twenty per cent of the tax calculated under said subsection (a) for such income year, without reduction of the tax so calculated by the amount of any credit against such tax. The additional amount of tax determined under this subsection for any income year shall constitute a part of the tax imposed by the provisions of said subsection (a) and shall become due and be paid, collected and enforced as provided in this chapter.
(4) With respect to income years commencing on or after January 1, 2004, and prior to January 1, 2005, any company subject to the tax imposed in accordance with subsection (a) of this section shall pay, for each such income year, an additional tax in an amount equal to twenty-five per cent of the tax calculated under said subsection (a) for such income year, without reduction of the tax so calculated by the amount of any credit against such tax, except that any company that pays the minimum tax of two hundred fifty dollars under section 12-219 or 12-223c for such income year shall not be subject to the additional tax imposed by this subdivision. The additional amount of tax determined under this subdivision for any income year shall constitute a part of the tax imposed by the provisions of said subsection (a) and shall become due and be paid, collected and enforced as provided in this chapter.
(5) With respect to income years commencing on or after January 1, 2006, and prior to January 1, 2007, any company subject to the tax imposed in accordance with subsection (a) of this section shall pay, except when the tax so calculated is equal to two hundred fifty dollars, for each such income year, an additional tax in an amount equal to twenty per cent of the tax calculated under said subsection (a) for such income year, without reduction of the tax so calculated by the amount of any credit against such tax. The additional amount of tax determined under this subsection for any income year shall constitute a part of the tax imposed by the provisions of said subsection (a) and shall become due and be paid, collected and enforced as provided in this chapter.
(6) (A) With respect to income years commencing on or after January 1, 2009, and prior to January 1, 2012, any company subject to the tax imposed in accordance with subsection (a) of this section shall pay, for each such income year, except when the tax so calculated is equal to two hundred fifty dollars, an additional tax in an amount equal to ten per cent of the tax calculated under said subsection (a) for such income year, without reduction of the tax so calculated by the amount of any credit against such tax. The additional amount of tax determined under this subsection for any income year shall constitute a part of the tax imposed by the provisions of said subsection (a) and shall become due and be paid, collected and enforced as provided in this chapter.
(B) Any company whose gross income for the income year was less than one hundred million dollars shall not be subject to the additional tax imposed under subparagraph (A) of this subdivision. This exception shall not apply to companies filing a combined return for the income year under section 12-223a or a unitary return under subsection (d) of section 12-218d.
(7) (A) With respect to income years commencing on or after January 1, 2012, and prior to January 1, 2018, any company subject to the tax imposed in accordance with subsection (a) of this section shall pay, for each such income year, except when the tax so calculated is equal to two hundred fifty dollars, an additional tax in an amount equal to twenty per cent of the tax calculated under said subsection (a) for such income year, without reduction of the tax so calculated by the amount of any credit against such tax. The additional amount of tax determined under this subsection for any income year shall constitute a part of the tax imposed by the provisions of said subsection (a) and shall become due and be paid, collected and enforced as provided in this chapter.
(B) Any company whose gross income for the income year was less than one hundred million dollars shall not be subject to the additional tax imposed under subparagraph (A) of this subdivision. With respect to income years commencing on or after January 1, 2012, and prior to January 1, 2016, this exception shall not apply to companies filing a combined return for the income year under section 12-223a or a unitary return under subsection (d) of section 12-218d. With respect to income years commencing on or after January 1, 2016, and prior to January 1, 2018, this exception shall not apply to taxable members of a combined group that files a combined unitary tax return.
(8) (A) With respect to income years commencing on or after January 1, 2018, and prior to January 1, 2021, any company subject to the tax imposed in accordance with subsection (a) of this section shall pay, for such income year, except when the tax so calculated is equal to two hundred fifty dollars, an additional tax in an amount equal to ten per cent of the tax calculated under said subsection (a) for such income year, without reduction of the tax so calculated by the amount of any credit against such tax. The additional amount of tax determined under this subsection for any income year shall constitute a part of the tax imposed by the provisions of said subsection (a) and shall become due and be paid, collected and enforced as provided in this chapter.
(B) Any company whose gross income for the income year was less than one hundred million dollars shall not be subject to the additional tax imposed under subparagraph (A) of this subdivision. This exception shall not apply to taxable members of a combined group that files a combined unitary tax return.
(c) Each taxable member of a combined group required to file a combined unitary tax return pursuant to section 12-222 shall calculate such member's tax under subsection (a) of this section, by multiplying such member's net income apportioned to this state, as provided in subsection (c) of section 12-218e, by the tax rate set forth in this section.
(1949 Rev., S. 1897; 1951, 1953, June, 1955, S. 1089d; 1957, P.A. 515, S. 1; 649, S. 1; 1959, P.A. 394, S. 1; 510; 1961, P.A. 604, S. 2; February, 1965, P.A. 147; 461, S. 7; 1969, P.A. 674; June, 1969, P.A. 1, S. 13; 1971, P.A. 683, S. 1; June, 1971, P.A. 5, S. 111; 1972, P.A. 271, S. 1; 285, S. 6; P.A. 73-350, S. 6, 27; 73-442, S. 4; P.A. 75-101, S. 1, 2; 75-213, S. 1, 53; P.A. 77-476, S. 1, 3; 77-499, S. 1, 2; P.A. 80-406, S. 4, 5; 80-483, S. 54, 186; P.A. 81-472, S. 15, 159; June Sp. Sess. P.A. 83-1, S. 1, 15; P.A. 85-431, S. 1, 2; 85-474, S. 1, 2; P.A. 88-222, S. 1, 2; P.A. 89-16, S. 1, 31; 89-211, S. 22; 89-251, S. 20, 203; P.A. 90-28, S. 1; June Sp. Sess. P.A. 91-3, S. 99, 168; P.A. 92-152, S. 1; P.A. 93-74, S. 5, 67; 93-199, S. 4, 6; P.A. 94-4, S. 1, 2; May 25 Sp. Sess. P.A. 94-1, S. 45, 130; P.A. 95-160, S. 32, 69; P.A. 96-139, S. 12, 13; 96-197, S. 3, 11; P.A. 98-110, S. 13, 27; 98-244, S. 6, 35; June Sp. Sess. P.A. 98-1, S. 106, 121; P.A. 03-2, S. 32; June 30 Sp. Sess. P.A. 03-1, S. 87; P.A. 05-251, S. 62; P.A. 06-186, S. 66; June Sp. Sess. P.A. 09-3, S. 94; P.A. 11-6, S. 76; P.A. 13-184, S. 73; P.A. 15-244, S. 83, 142; June Sp. Sess. P.A. 15-5, S. 139, 140; P.A. 19-117, S. 341.)
History: 1959 acts changed technical language of statute, added exclusion in Subsec. (2) for companies which elect not to be subject to such tax, applied 3.75% rate to net income received in each year as opposed to only those years between 1953 and 1958; 1961 act added reference to chapter 212a, changed tax rate to 5% and changed technical language of statute; 1965 acts added Subdiv. (5) excepting nonprofit cooperative ownership housing corporations when residence is restricted to corporation members and corporation ownership is restricted to residents from payment of tax and restricted 5% tax rates to years beginning before January 1, 1966, and increased rates for years thereafter to 5.25%; 1969 acts specified stock and nonstock corporations in Subdiv. (5) and added Subdiv. (6) excepting cooperative housing corporations where there is no taxable income to corporation from payment of tax, added new Subdivs. (4) and (5) detailing companies formerly mentioned by chapter reference only in Subdiv. (3) and renumbering remaining Subdivs. accordingly, specified companies “not subject to the tax imposed by this part” in Subdiv. (6), formerly (4), changed tax rates in Subdiv. (7), formerly (5), to 5.25% for years beginning after January 1, 1971, and, in the case of companies other than telephone companies, made 5.25% rate applicable to years before January 1, 1969, and set rate for period between that date and January 1, 1971, at 8%; 1971 acts deleted proviso that minimum tax shall not be less than minimum tax under Sec. 12-219, substituted “additional” for “minimum” re tax under Sec. 12-219, deleted Subdiv. (5), renumbering following Subdivs. accordingly, and changed references to 1971 to 1973; 1972 acts included DISC companies in Subdiv. (2), changed tax rates in Subdiv. (7) to 8% without exception and deleted provisions concerning tax on telephone companies; P.A. 73-350 rewrote Subdiv. (1) to apply to insurance companies for years before January 1, 1973, and to insurance companies incorporated or organized under laws of other state or foreign company on or after that date, deleted Subdiv. (4) renumbering subsequent Subdivs. accordingly and added proviso that tax rate as of January 1, 1974, applicable to companies subject to tax under provisions of section will be 2%, effective May 9, 1973, and applicable to income years beginning on or after January 1, 1973; P.A. 73-442 included foreign municipal electric utilities under provisions of section and specifically excluded such utilities in Subdiv. (2) of exception; P.A. 75-101 added new Subdiv. (7) exempting organizations promoting success or defeat of political candidates, parties, questions, constitutional amendments etc. from payment of tax, effective May 12, 1975, and applicable to income years commencing on or after January 1, 1973; P.A. 75-213 changed 8% rate to 10% for income years beginning on or after January 1, 1975; P.A. 77-476 deleted references to foreign municipal electric utilities; P.A. 77-499 required payment for owning or leasing property in state in corporate capacity or as unincorporated association taxable for federal income tax purposes or for maintaining an office in state; P.A. 80-406 added Subdiv. (8) exempting certain companies engaged in research, design, manufacture, sale or installation of alternative energy systems from payment of tax until July 1, 1985; P.A. 80-483 deleted reference to building and loan associations; P.A. 81-472 made technical changes; June Sp. Sess. P.A. 83-1 increased the rate of tax from 10% to 11.5%, effective July 1, 1983, and applicable to income years of corporations commencing on or after January 1, 1983; P.A. 85-431 added provision allowing for retroactive exemption to date of incorporation for certain nonprofit corporations; P.A. 85-474 provided that exemption under Subdiv. (8) for alternative energy system companies shall not be allowed with respect to any income year commencing on or after January 1, 1988, instead of after July 1, 1985; P.A. 88-222 expanded the corporate tax exemption of Subdiv. (8) to include any company which is not owned or controlled, directly or indirectly, by any other company and extended the exemption until January 1, 1993, effective May 28, 1988, and applicable to income years of corporations commencing on or after January 1, 1988; P.A. 89-16 added Subsec. (b) imposing an additional tax as a percentage of the tax under Subsec. (a), effective March 23, 1989, and applicable to income years of corporations commencing on or after January 1, 1989; P.A. 89-211 clarified reference to the Internal Revenue Code of 1986; P.A. 89-251 amended Subsec. (b) by increasing the additional tax imposed under Sec. 1 of P.A. 89-16 from 15% to 20% of the tax calculated under Subsec. (a), effective July 1, 1989, and applicable to income years commencing on or after January 1, 1989; P.A. 90-28 made technical changes in the list of corporations in Subsec. (a) not subject to tax; June Sp. Sess. P.A. 91-3 amended Subsec. (b) to provide that the 20% additional tax would be applicable with respect to income years commencing prior to January 1, 1992, and to impose a 10% additional tax applicable with respect to income years commencing on or after January 1, 1992, and prior to January 1, 1993, effective August 22, 1991, and applicable to income years of corporations commencing on or after January 1, 1991; P.A. 92-152 added new Subsec. (a)(8) exempting corporation engaged in the research, design, manufacture or sale of aero-derived gas turbine systems and extended the exemptions for Subdivs. (7) and (8) until January 1, 1998; P.A. 93-74 added provisions reducing tax rates commencing on and after January 1, 1995, effective May 19, 1993, and applicable to taxable years commencing on and after January 1, 1995; P.A. 93-199 expanded exemption in Subdiv. (7) to include companies engaged in research, design, manufacture, sale or installation of motor vehicles powered by electricity, natural gas or solar energy, effective July 1, 1993, and applicable to taxable years commencing on or after January 1, 1993; P.A. 94-4 in Subdiv. (5) of Subsec. (a) eliminated provision requiring cooperative housing corporations to have no taxable income, effective April 7, 1994, and applicable for income years commencing on or after January 1, 1990; May Sp. Sess. P.A. 94-1 amended Subsec. (a) to conform section with revisions made in Sec. 5 of P.A. 93-74, effective April 7, 1994; P.A. 95-160 amended Subsec. (a) to decrease tax rate from 11% to 10.75% for the income years commencing on or after January 1, 1996, and prior to January 1, 1997, 9.5% for the income years commencing on or after January 1, 1998, and prior to January 1, 1999, 8.5% for the income years commencing on or after January 1, 1999, and prior to January 1, 2000, and 7.5% for income years commencing on or after January 1, 2000, effective June 1, 1995; P.A. 96-139 amended effective date of P.A. 95-160 to clarify applicability to income years commencing on or after January 1, 1996; P.A. 96-197 amended Subsec. (a) to reorganize provisions and added Subdiv. (3) re general partners of a partnership and made other technical changes, effective June 3, 1996, and applicable to income years commencing on or after January 1, 1996; P.A. 98-110 amended Subsec. (a)(2) to exempt domestic insurance companies and make technical changes, effective May 19, 1998, and applicable to income years commencing on or after January 1, 1999; P.A. 98-244 amended Subsec. (a)(2) to exempt S corporations from the minimum tax under Sec. 12-219 for income years commencing on or after January 1, 2001, and to exempt foreign-sourced income of non-United-States corporations from the corporation business tax, effective June 8, 1998, and applicable to income years commencing on or after January 1, 1998; June Sp. Sess. P.A. 98-1 amended Subsec. (a)(2) to add commodities, effective June 24, 1998; P.A. 03-2 added Subsec. (b)(3) re surcharge for the 2003 income year, effective February 28, 2003, and applicable to income years commencing on or after January 1, 2003; June 30 Sp. Sess. P.A. 03-1 amended Subsec. (b) to include in surcharge provided under Subdiv. (3) amounts calculated under Sec. 91 of P.A. 03-1 of the June 30 special session and to add Subdiv. (4) re surcharge for the 2004 income year, effective August 16, 2003, and applicable to income years commencing on or after January 1, 2003; P.A. 05-251 amended Subsec. (b) by deleting references to Sec. 91 of June 30 Sp. Sess. P.A. 03-1 in Subdivs. (3) and (4) and by adding Subdivs. (5) and (6) re surcharge for 2006 and 2007 income years, respectively, effective June 30, 2005, and applicable to income years commencing on or after January 1, 2006; P.A. 06-186 deleted former Subsec. (b)(6) re surcharge in income years commencing on or after January 1, 2007, and prior to January 1, 2008, effective July 1, 2006, and applicable to income years commencing on or after January 1, 2006; June Sp. Sess. P.A. 09-3 amended Subsec. (b) to add Subdiv. (6) re surcharge for 2009, 2010 and 2011 income years and exemption for companies with gross income less than $100,000,000, effective September 9, 2009, and applicable to income years commencing on or after January 1, 2009; P.A. 11-6 amended Subsec. (b) to add Subdiv. (7) re 20% surcharge for 2012 and 2013 income years and exemption for companies with gross income less than $100,000,000, effective May 4, 2011, and applicable to income years commencing on or after January 1, 2011; P.A. 13-184 amended Subsec. (b)(7)(A) to extend surcharge to income years prior to January 1, 2016, effective June 18, 2013; P.A. 15-244 amended Subsec. (b)(7)(A) to extend surcharge to January 1, 2018, amended Subsec. (b)(7)(B) to provide that for income years commencing on or after January 1, 2015, and prior to January 1, 2018, exception shall not apply to taxable members of combined group filing a combined unitary tax return, added Subsec. (b)(8)(A) re surcharge for income year commencing on or after January 1, 2018, and added Subsec. (b)(8)(B) re exemption for companies with gross income less than $100,000,000, and added Subsec. (c) re calculation of tax under Subsec. (a) for taxable member of combined group required to file combined unitary tax return, effective June 30, 2015, and applicable to income years commencing on or after January 1, 2015; June Sp. Sess. P.A. 15-5 changed effective date of P.A. 15-244, S. 83 and 142, from June 30, 2015, and applicable to income years commencing on or after January 1, 2015, to January 1, 2016, and applicable to income years commencing on or after that date, effective June 30, 2015, and amended Subsec. (b)(7)(B) to provide that exception not apply to companies filing combined return or unitary return with respect to income years commencing prior to January 1, 2016, rather than January 1, 2015, and exception not apply to taxable members of a combined group that files a combined unitary tax return with respect to income years commencing on or after January 1, 2016, rather than January 1, 2015, and amended Subsec. (b)(8)(A) to provide that additional tax apply to income years commencing prior to January 1, 2019, effective January 1, 2016, and applicable to income years commencing on or after that date; P.A. 19-117 amended Subsec. (b)(8) to replace “January 1, 2019” with “January 1, 2021”, effective June 26, 2019, and applicable to income years commencing on or after January 1, 2019.