(1) (a) Except as provided in Subsections (1)(c) through (f), the commission shall assess the amount of taxes imposed under this part, and any penalties and interest, within six years after a taxpayer files a return. (b) Except as provided in Subsections (1)(c) through (f), if the commission does not make an assessment under Subsection (1)(a) within six years, the commission may not commence a proceeding for the collection of the taxes after the expiration of the six-year period. (c) Notwithstanding Subsections (1)(a) and (b), the commission may make an assessment or commence a proceeding to collect a tax at any time if a deficiency is due to: (i) fraud; or (ii) failure to file a return. (d) Notwithstanding Subsections (1)(a) and (b), beginning on July 1, 1998, the commission may extend the period to make an assessment or to commence a proceeding to collect the tax under this part if: (i) the six-year period under this Subsection (1) has not expired; and (ii) the commission and the taxpayer sign a written agreement: (A) authorizing the extension; and (B) providing for the length of the extension. (e) If the commission delays an audit at the request of a taxpayer, the commission may make an assessment as provided in Subsection (1)(f) if: (i) the taxpayer subsequently refuses to agree to an extension request by the commission; and (ii) the six-year period under this Subsection (1) expires before the commission completes the audit. (f) An assessment under Subsection (1)(e) shall be: (i) for the time period for which the commission could not make an assessment because of the expiration of the six-year period; and (ii) in an amount equal to the difference between: (A) the commission's estimate of the amount of taxes the taxpayer would have been assessed for the time period described in Subsection (1)(f)(i); and (B) the amount of taxes the taxpayer actually paid for the time period described in Subsection (1)(f)(i).

(a) Except as provided in Subsections (1)(c) through (f), the commission shall assess the amount of taxes imposed under this part, and any penalties and interest, within six years after a taxpayer files a return.

(b) Except as provided in Subsections (1)(c) through (f), if the commission does not make an assessment under Subsection (1)(a) within six years, the commission may not commence a proceeding for the collection of the taxes after the expiration of the six-year period.

(c) Notwithstanding Subsections (1)(a) and (b), the commission may make an assessment or commence a proceeding to collect a tax at any time if a deficiency is due to: (i) fraud; or (ii) failure to file a return.

(i) fraud; or

(ii) failure to file a return.

(d) Notwithstanding Subsections (1)(a) and (b), beginning on July 1, 1998, the commission may extend the period to make an assessment or to commence a proceeding to collect the tax under this part if: (i) the six-year period under this Subsection (1) has not expired; and (ii) the commission and the taxpayer sign a written agreement: (A) authorizing the extension; and (B) providing for the length of the extension.

(i) the six-year period under this Subsection (1) has not expired; and

(ii) the commission and the taxpayer sign a written agreement: (A) authorizing the extension; and (B) providing for the length of the extension.

(A) authorizing the extension; and

(B) providing for the length of the extension.

(e) If the commission delays an audit at the request of a taxpayer, the commission may make an assessment as provided in Subsection (1)(f) if: (i) the taxpayer subsequently refuses to agree to an extension request by the commission; and (ii) the six-year period under this Subsection (1) expires before the commission completes the audit.

(i) the taxpayer subsequently refuses to agree to an extension request by the commission; and

(ii) the six-year period under this Subsection (1) expires before the commission completes the audit.

(f) An assessment under Subsection (1)(e) shall be: (i) for the time period for which the commission could not make an assessment because of the expiration of the six-year period; and (ii) in an amount equal to the difference between: (A) the commission's estimate of the amount of taxes the taxpayer would have been assessed for the time period described in Subsection (1)(f)(i); and (B) the amount of taxes the taxpayer actually paid for the time period described in Subsection (1)(f)(i).

(i) for the time period for which the commission could not make an assessment because of the expiration of the six-year period; and

(ii) in an amount equal to the difference between: (A) the commission's estimate of the amount of taxes the taxpayer would have been assessed for the time period described in Subsection (1)(f)(i); and (B) the amount of taxes the taxpayer actually paid for the time period described in Subsection (1)(f)(i).

(A) the commission's estimate of the amount of taxes the taxpayer would have been assessed for the time period described in Subsection (1)(f)(i); and

(B) the amount of taxes the taxpayer actually paid for the time period described in Subsection (1)(f)(i).

(2) (a) Except as provided in Subsection (2)(b), the commission may not make a credit or refund unless the taxpayer files a claim with the commission within six years of the date of overpayment. (b) Notwithstanding Subsection (2)(a), beginning on July 1, 1998, the commission shall extend the period for a taxpayer to file a claim under Subsection (2)(a) if: (i) the six-year period under Subsection (2)(a) has not expired; and (ii) the commission and the taxpayer sign a written agreement: (A) authorizing the extension; and (B) providing for the length of the extension.

(a) Except as provided in Subsection (2)(b), the commission may not make a credit or refund unless the taxpayer files a claim with the commission within six years of the date of overpayment.

(b) Notwithstanding Subsection (2)(a), beginning on July 1, 1998, the commission shall extend the period for a taxpayer to file a claim under Subsection (2)(a) if: (i) the six-year period under Subsection (2)(a) has not expired; and (ii) the commission and the taxpayer sign a written agreement: (A) authorizing the extension; and (B) providing for the length of the extension.

(i) the six-year period under Subsection (2)(a) has not expired; and

(ii) the commission and the taxpayer sign a written agreement: (A) authorizing the extension; and (B) providing for the length of the extension.

(A) authorizing the extension; and

(B) providing for the length of the extension.