RSA 77-A:9 — Extension of Time for Returns. –

For good cause, the commissioner may extend the time within which a taxpayer is required to file a return, and if such return is filed during the period of extension no penalty may be imposed for failure to file the return at the time required by this chapter, but the taxpayer shall be liable for interest and late payment charges as prescribed in RSA 21-J:28, 32, or 33. Failure to file the return during the period of the extension shall void the extension.