(a) Except as otherwise provided in this Code section, the amount of income tax imposed by this chapter shall be assessed within the time periods specified in Code Section 48-2-49.

(b) (1) In the case of income received during the lifetime of a decedent, by the estate of a decedent during the period of administration, or by a corporation, the tax shall be assessed within three years after the return is filed, and any proceeding in court without assessment for the collection of the tax shall begin within 18 months after written request for the commencement of the proceeding (filed after the return is made) by the personal representative or other fiduciary representing the estate of the decedent or by the corporation. No such proceeding shall begin after the expiration of three years from the date the return is filed. This paragraph shall not apply in the case of a corporation unless:

(A) The written request notifies the commissioner that the corporation contemplates dissolution at or before the expiration of the 18 month period;

(B) The dissolution is begun in good faith before the expiration of the 18 month period; and

(C) The dissolution is completed.

(2) If the taxpayer omits from gross income an amount properly includable in gross income which exceeds 25 percent of the amount of gross income less business expenses stated in the return, the tax may be assessed or a proceeding in court for the collection of the tax may begin without assessment at any time within six years after the return is filed.

(3) If the taxpayer omits from gross income an amount properly includable in gross income as an amount distributed in liquidation of a corporation, the tax may be assessed or a proceeding in court for the collection of the tax may begin without assessment at any time within five years after the return is filed.

(c) When the assessment of any income tax has been made within the period of limitation properly applicable to the assessment, the tax may be collected by execution, provided that the commissioner may transmit such execution electronically. The general provisions for tax executions as contained in Chapter 3 of this title shall apply to executions pursuant to this subsection.

(d) Reserved.

(e) (1) Except as provided in Code Section 48-7-53, when a taxpayer's amount of net income for any year under this chapter as returned to the United States Department of the Treasury is changed or corrected by the commissioner of internal revenue or other officer of the United States of competent authority, the taxpayer, within 180 days after the final determination date of the changed or corrected net income, shall make a return to the commissioner of the changed or corrected income, and the commissioner shall make assessment or the taxpayer shall claim a refund based on the change or correction within one year from the date the return required by this paragraph is filed. If the taxpayer does not make the return reflecting the changed or corrected net income and the commissioner receives from the United States government or one of its agents a report reflecting the changed or corrected net income, the commissioner shall make assessment for taxes due based on the change or correction within five years from the date the report from the United States government or its agent is actually received. If he or she chooses, the commissioner shall have the authority to establish a de minimis amount upon which a taxpayer shall not be required to comply with this subsection. For purposes of this subsection the final determination date shall be determined as follows:

(A) Except as provided in subparagraph (B) of this paragraph, the final determination date is the first day on which no changes or corrections for a particular audit remain to be finally determined, whether by agreement, or, if appealed or contested, by a final decision with respect to which all rights of appeal have been waived or exhausted. For agreements required to be signed by the commissioner of internal revenue and the taxpayer, the final determination date is the date on which the last party signed the agreement; or

(B) If the taxpayer filed as a member of a combined or consolidated group, the final determination date is the first day on which no related changes or corrections for a particular audit remain to be finally determined for the entire group.

(2) In the event the taxpayer fails to notify the commissioner of the final determination of his or her United States income taxes, the commissioner shall proceed to determine, upon evidence that the commissioner has brought to his or her attention or that he or she otherwise acquires, the corrected income of the taxpayer for the fiscal or calendar year. If additional tax is determined to be due, the tax shall be assessed and collected. If it is determined that there has been an overpayment of tax for the year, the taxpayer, by his or her failure to notify the commissioner as required in paragraph (1) of this subsection, shall forfeit his or her right to any refund due by reason of the change or correction. A taxpayer who so fails to notify the commissioner, however, shall be entitled to equitable recoupment of 90 percent of any overpayment so determined against any additional tax liability so determined, the remaining 10 percent of the overpayment being totally forfeited as a penalty for failure to make a return as required by paragraph (1) of this subsection.