Report of changed, corrected taxable income

13. If the amount of the taxable income for any year of any taxpayer as returned to the United States Treasury Department is changed or corrected by the Commissioner of Internal Revenue or other officer of the United States or other competent authority, or where a renegotiation of a contract or subcontract with the United States results in a change in said taxable income, or where a recovery of a war loss results in a computation or recomputation of any tax imposed by the United States, such taxpayer shall report such changed or corrected taxable income, or the results of such renegotiation, or such computation or recomputation, within 90 days after the final determination of such change or correction or renegotiation, or such computation or recomputation, or as required by the director, and shall concede the accuracy of such determination or state wherein it is erroneous. Any taxpayer filing an amended return with such department shall also file within 90 days thereafter an amended report with the director. The periods of limitation to make deficiency assessments under R.S.54:49-6 and to file claims for refund under R.S.54:49-14 shall commence to run for additional four year periods from the date that taxable income is finally changed or corrected by the Commissioner of Internal Revenue; provided, that the additional periods of limitation shall only be applicable to the increase or decrease in tax attributable to the adjustments in such changed or corrected taxable income.