N.C. Gen. Stat. § 105-241.10

The limitations in this section apply when a taxpayer files a timely return reflecting a federal determination that affects the amount of State tax payable and the general statute of limitations for requesting a refund or proposing an assessment of the State tax has expired. A return reflecting a federal determination is timely if it is filed within the time required by G.S. 105-130.20, 105-159, 105-160.8, or 105-163.6A, as appropriate. A federal determination has the same meaning as defined in G.S. 105-228.90. The limitations are:

(1) Refund. - A taxpayer is allowed a refund only if the refund is the result of adjustments related to the federal determination.

(2) Assessment. - A taxpayer is liable for additional tax only if the additional tax is the result of adjustments related to the federal determination. A proposed assessment may not include an amount that is outside the scope of this liability.