G.S. 105-151

(a) An individual who is a resident of this State is allowed a credit against the taxes imposed by this Part for income taxes imposed by and paid to another state or country on income taxed under this Part, subject to the following conditions:

(1) The credit is allowed only for taxes paid to another state or country on income derived from sources within that state or country that is taxed under its laws irrespective of the residence or domicile of the recipient, except that whenever a taxpayer who is deemed to be a resident of this State under the provisions of this Part is deemed also to be a resident of another state or country under the laws of that state or country, the Secretary may allow a credit against the taxes imposed by this Part for taxes imposed by and paid to the other state or country on income taxed under this Part.

(2) The fraction of the gross income, as calculated under the Code and adjusted as provided in G.S. 105-134.6 and G.S. 105-134.6A, that is subject to income tax in another state or country shall be ascertained, and the North Carolina net income tax before credit under this section shall be multiplied by that fraction. The credit allowed is either the product thus calculated or the income tax actually paid the other state or country, whichever is smaller.

(3) Receipts showing the payment of income taxes to another state or country and a true copy of a return or returns upon the basis of which the taxes are assessed shall be filed with the Secretary when the credit is claimed. If credit is claimed on account of a deficiency assessment, a true copy of the notice assessing or proposing to assess the deficiency, as well as a receipt showing the payment of the deficiency, shall be filed.