RSA 78-C:3 — Returns and Declarations. –

I. Every person engaged in the production of refined petroleum products during a taxable period shall, on or before the fifteenth day of the first month following the expiration of the taxable period, make a return to the commissioner under such regulations and in such form or manner as the commissioner may prescribe. Returns shall contain full data as required by the commissioner for correct computation of the tax hereunder. All returns shall be signed by the taxpayer or by his authorized representative, subject to the pains and penalties of perjury.
II. At the same time the return is filed as required by paragraph I, every person who produces refined petroleum products shall, in addition, file a declaration of its estimated production of refined petroleum products and estimated tax thereon for the subsequent taxable period. Such estimated production of refined petroleum products and estimated tax thereon shall be at least equal to the production and tax on the return filed therewith, unless for good cause the commissioner permits the taxpayer to make a lesser estimate.
III. Any person who fails to file any return or declaration at the time prescribed in this section shall pay at the time the return or declaration is filed, in addition to any tax liability and without assessment or demand, a late filing fee of $100 for each day or fraction thereof which has elapsed between the prescribed filing date and the date of actual filing.