I. Every business enterprise having gross business receipts in excess of $250,000 as defined by N.H. Rev. Stat. § 77-E:1, X, during the taxable period or the enterprise value tax base of which is greater than $250,000 shall, on or before the fifteenth day of the third month in the case of enterprises required to file a United States partnership tax return, the fifteenth day of the fifth month in the case of enterprises required to file a United States exempt organization return, and the fifteenth day of the fourth month in the case of all other business enterprises, following expiration of its taxable period, make a return to the commissioner. For tax years beginning January 1, 2015, the commissioner shall biennially adjust these threshold amounts rounding to the nearest $1,000 based on the 2-year (24-month) percentage change in the Consumer Price Index for All Urban Consumers, Northeast Region as published by the Bureau of Labor Statistics, United States Department of Labor using the amount published for the month of June in the year prior to the start of the tax year. All returns shall be signed by the business enterprise or by its authorized representative, subject to the pains and penalties of perjury and the penalties provided in N.H. Rev. Stat. § 21-J:39.
II. Every business enterprise shall in addition file a declaration of its estimated business enterprise tax for its subsequent taxable period; provided, however, if the estimated tax is less than $260, a declaration need not be filed; and provided further that a declaration shall be filed at the end of any quarter thereafter in which estimated tax exceeds $260. The declaration shall be filed when payments are due under N.H. Rev. Stat. § 77-E:6.