N.C. Gen. Stat. § 105-555
The board of trustees of an Authority may repeal a tax levied under this Article or decrease the tax rate of a tax levied under this Article. The same restrictions that apply to the levy of a tax or an increase in a tax rate under this Article apply to the repeal of the tax or a decrease in the tax rate.
A tax repeal or a tax decrease becomes effective on the date set by the board of trustees in the resolution repealing or decreasing the tax. The effective date must be on the first day of a month and may not be earlier than the first day of the second month after the board of trustees adopts the resolution. Repeal or decrease of a tax levied under this Article does not affect the rights or liabilities of an Authority, a taxpayer, or another person arising before the repeal or decrease.
N.C. Gen. Stat. § 105-555