(a) Credit allowed. -- There shall be allowed to eligible taxpayers a credit against the taxes imposed by article thirteen, thirteen-a or twenty-three of this chapter, for industrial expansion or revitalization, and for eligible research and development projects and for qualified housing development projects. The amount of credit shall be determined as hereinafter provided in this section.

(b) Qualified investment for industrial expansion; July 1, 1969 - March 31, 1978. -- For property purchased for industrial expansion during the period beginning July 1, 1969, and ending March 31, 1978, the amount of allowable credit shall be equal to ten percent of the qualified investment (as determined in section four) made for industrial expansion, and shall reduce the business and occupation tax liability of the industrial taxpayer under article thirteen of this chapter, subject to the following conditions and limitations:

(1) The amount of credit allowable shall be applied over a ten-year period, at the rate of one tenth thereof per taxable year, beginning with the taxable year in which the qualified investment is first placed in service or use in this state.

(2) The amount of annual credit allowed shall not reduce the business and occupation tax under article thirteen of this chapter, below fifty percent of the amount which would be imposed for such taxable year in the absence of this credit against tax, computed before application of the annual exemption allowed by section three, article thirteen of this chapter.

(3) No carryover to a subsequent taxable year or carryback to a prior taxable year shall be allowed for the amount of any unused portion of any annual credit allowance. Such unused credit shall be forfeited.

(c) Qualified investment for industrial expansion; April 1, 1978 - February 28, 1985. -- For property purchased for industrial expansion during the period beginning March 1, 1978, and ending February 28, 1985, the amount of allowable credit shall be equal to ten percent of the qualified investment (as determined in section four) made for industrial expansion, and shall reduce the business and occupation tax liability of the industrial taxpayer under section two-b, two-h and two-m, article thirteen of this chapter, subject to the following conditions and limitations:

(1) The amount of credit allowable shall be applied over a ten-year period, at the rate of one tenth thereof per taxable year, beginning with the taxable year in which the qualified investment is first placed in service or use in this state.

(2) The amount of annual credit allowed shall not reduce the business and occupation taxes imposed by section two, article thirteen of this chapter, under sections two-b, two-h and two-m, article thirteen of this chapter, below fifty percent of the amount which would be imposed for such taxable year, in the absence of this credit against tax, computed before application of the annual exemption allowed by section three, article thirteen of this chapter: Provided, That the tax under section two-h of said article thirteen, shall not be reduced by more than fifty percent of the tax attributable to the privilege of manufacturing for another, which privilege would be taxable under section two-b of said article thirteen, if title to the raw materials involved in the manufacturing process were vested in the taxpayer exercising the privilege taxable under section two-h of said article thirteen.

(3) No carryover to a subsequent taxable year or carryback to a prior taxable year shall be allowed for the amount of any unused portion of any annual credit allowance. Such unused credit shall be forfeited.

(d) Eligible investment for industrial revitalization; July 1, 1981 - February 28, 1985. -- For property purchased for industrial revitalization during the period beginning July 1, 1981, and ending February 28, 1985, the amount of allowable credit shall be equal to ten percent of the eligible investment (as determined under section four) made for industrial revitalization, and shall reduce the business and occupation tax under sections two-b and two-h, article thirteen of this chapter, subject to the following conditions and limitations:

(1) The allowable credit shall be applied over a ten-year period at the rate of one tenth of the amount thereof per taxable year, beginning with the taxable year in which the eligible investment is first placed in service or use in this state.

(2) The amount of annual credit allowed shall not reduce the business and occupation taxes imposed by section two, article thirteen of this chapter, under sections two-b and two-h of said article, below fifty percent of the amount which would be imposed for the taxable year in the absence of this credit against tax, computed before application of the annual exemption allowed by section three, article thirteen of this chapter: Provided, That the tax under section two-h of said article thirteen, shall not be reduced by more than fifty percent of the tax attributable to the privilege of manufacturing for another, which privilege would be taxable under section two-b of said article thirteen, if title to the raw materials involved in the manufacturing process were vested in the taxpayer exercising the privilege taxable under section two-h of said article thirteen.

(3) When in any taxable year the eligible industrial taxpayer is entitled to claim credit under both this subsection (d) and under subsections (b) or (c), or both, of this section, the total amount of all credits allowed under this section shall not exceed the fifty percent rule outlined in paragraph (2) of this subsection (d).

(4) No carryover to a subsequent taxable year or carryback to a prior taxable year shall be allowed for the amount of any unused portion of any annual credit allowance. Any unused credit shall be forfeited.

(5) No credit shall be allowed under this section for any property purchased for industrial revitalization prior to July 1, 1981.

(e) Eligible investment for industrial expansion or revitalization after February 28, 1985. -- For property purchased for industrial expansion or industrial revitalization on or after March 1, 1985, the amount of allowable credit shall be equal to ten percent of the eligible investment (as determined in section four) made for industrial expansion or industrial revitalization, and shall reduce the business and occupation tax imposed under article thirteen of this chapter subject to the following conditions and limitations:

(1) The amount of credit allowable shall be applied over a ten-year period, at the rate of one-tenth thereof per taxable year, beginning with the taxable year in which the eligible investment is first placed in service or use in this state.

(2) The amount of annual credit allowed shall not reduce the business and occupation taxes imposed by article thirteen of this chapter, below fifty percent of the amount which would be imposed for such taxable year in the absence of this credit against tax, computed before application of the annual exemption allowed by section three, article thirteen of this chapter.

(3) When in any taxable year the industrial taxpayer is entitled to claim credit under this subsection (e) and under subsections (b), (c) or (d) of this section (or any combinations thereof), the total amount of all credits allowed under this section shall not exceed the fifty percent rule outlined in paragraph (2) of this subsection (e).

(4) No carryover to a subsequent taxable year or carryback to a prior taxable year shall be allowed for the amount of any unused portion of any annual credit allowance. Such unused credit shall be forfeited.

(5) When in any taxable year the industrial taxpayer is entitled to claim credit under this article and article thirteen-e of this chapter, the total amount of all such credits allowable for the taxable year shall not reduce the amount of business and occupation taxes imposed by article thirteen of this chapter, below fifty percent of the amount which would be imposed for such taxable year, computed before allowance of the annual exemption allowed by section three, article thirteen of this chapter.

(6) No credit shall be allowed under this subsection (e) or any property purchased on or after March 1, 1985, for which credit is allowed under article thirteen-c of this chapter.

(7) No credit shall be allowed under this subsection (e) or any property purchased for industrial expansion or industrial revitalization prior to March 1, 1985.

(f) Eligible investment for research and development project after June 30, 1985. -- For property and services purchased for an eligible research and development project on or after July 1, 1985, the amount of allowable credit shall be equal to ten percent of the eligible investment (as determined in section five) made for an eligible research and development project, and shall reduce the business and occupation taxes under sections two-a, two-b, two-m, article thirteen of this chapter, subject to the following conditions and limitations:

(1) The allowable credit shall be applied over a ten-year period at the rate of one tenth of the amount thereof per taxable year, beginning with the taxable year in which the eligible investment is first placed in service or use in this state, or is expensed for federal income tax purposes.

(2) The amount of annual credit allowed shall not reduce the business and occupation taxes imposed by section two, article thirteen of this chapter, under section two-a of said article, on the business of producing natural resources; under section two-b of said article thirteen, on the business or manufacturing, compounding or preparing tangible personal property for sale; under section two-h of said article thirteen on the providing of a manufacturing service; and under section two-m of said article thirteen, on the business of generating electric power, below fifty percent of the amount which would be imposed for the taxable year in the absence of this credit against tax, computed before application of the annual exemption allowed by section three, article thirteen of this chapter.

(3) When in any taxable year the eligible taxpayer is entitled to claim credit under both this subsection (f) and subsections (b), (c), (d) or (e) of this section (or any combinations thereof), the total amount of all credits allowed under this section shall not exceed the fifty percent rule outlined in paragraph (2) of this subsection (f).

(4) No carryover to a subsequent tax year or carryback to a prior taxable year shall be allowed for the amount of any unused portion of any annual credit allowance. Any unused credit shall be forfeited.

(5) No credit shall be allowed under this subsection (f) for any property purchased for an eligible research and development project, when such property is used to determine the eligible investment under section four of this article, or determine the amount of credit allowable under article thirteen-c of this chapter.

(6) No credit shall be allowed under this subsection (f) for any property purchased for research and development prior to July 1, 1985.

(g) Eligible investment for qualified housing development project after June 30, 1986. -- For property and services purchased for a qualified housing development project on or after July 1, 1986, the amount of allowable credit shall be equal to ten percent of the eligible investment (as determined in section five-a) made for a qualified housing development project, and shall reduce the business and occupation taxes under sections two-c and two-e, article thirteen of this chapter, subject to the following conditions and limitations:

(1) The allowable credit shall be applied over a ten-year period at the rate of one tenth of the amount thereof per taxable year, beginning with the taxable year in which any combination of residential housing units (as defined in section five-a of this article) available for occupancy or occupied in the qualified housing development project is five or more residential housing units.

(2) The amount of annual credit allowed shall not reduce the business and occupation taxes imposed by section two, article thirteen of this chapter, under section two-c of said article on the business of selling tangible property and under section two-e on the business of contracting below fifty percent of the amount which would be imposed for the taxable year in the absence of this credit against tax, computed before application of the annual exemption allowed by section three, article thirteen of this chapter.

(3) When in any taxable year the eligible taxpayer is entitled to claim credit under both this subsection (g) and subsections (b), (c), (d), (e) or (f) of this section (or any combinations thereof), the total amount of all credits allowed under this section shall not exceed the fifty percent rule outlined in paragraph (2) of this subsection (g).

(4) No carryover to a subsequent tax year or carryback to a prior taxable year shall be allowed for the amount of any unused portion of any annual credit allowance. Any unused credit shall be forfeited.

(5) No credit shall be allowed under this subsection (g) for any property purchased for an eligible housing development project, when such property is used to determine the eligible investment under section four of this article, or determine the amount of credit allowable under article thirteen-c of this chapter.

(6) No credit shall be allowed under this subsection (g) for any property purchased for an eligible housing development project, when such property is used to determine the eligible investment under section four of this article, or determine the amount of credit allowable under article thirteen-c of this chapter.

(h) Credit limitation. -- The aggregate amount of credit allowable under this article and article thirteen-e of this chapter, against the taxes imposed by article thirteen of this chapter for the taxable year, shall in no event exceed fifty percent of the tax due for the taxable year, computed prior to application of the tax credits provided by this article and articles thirteen-c and thirteen-e of this chapter, and the annual exemption allowed provided by section three, article thirteen of this chapter.

(i) Application of credit after June 30, 1987. -- On and after July 1, 1987, the credits allowed under subsections (b), (c), (d), (e), (f) and (g) of this section shall be applied to and reduce the taxes imposed by articles thirteen, thirteen-a and twenty-three of this chapter: Provided, That this credit shall not reduce the sum of the net tax liability of the taxpayer under articles thirteen, thirteen-a and twenty-three of this chapter, for the taxable year below fifty percent of the amount thereof, determined before application of the credits allowed by this article and article thirteen-c or thirteen-e, or both, of this chapter.