An annual return is due within 45 days after the end of each calendar year. An annual return covers tax liabilities that accrue in the calendar year preceding the date the return is due.
A monthly return of a person other than an occasional importer is due within 22 days after the end of each month. A monthly return of an occasional importer is due by the 3rd of each month. A monthly return covers tax liabilities that accrue in the calendar month preceding the date the return is due.
N.C. Gen. Stat. § 105-449.90