N.J. Stat. § 54:4-34
Every owner of real property of the taxing district shall, on written request of the assessor, made by certified mail, render a full and true account of his name and real property and the income therefrom, in the case of income-producing property, and produce his title papers, and he may be examined on oath by the assessor, and if he shall fail or refuse to respond to the written request of the assessor within 45 days of such request, or to testify on oath when required, or shall render a false or fraudulent account, the assessor shall value his property at such amount as he may, from any information in his possession or available to him, reasonably determine to be the full and fair value thereof. No appeal shall be heard from the assessor's valuation and assessment with respect to income-producing property where the owner has failed or refused to respond to such written request for information within 45 days of such request or to testify on oath when required, or shall have rendered a false or fraudulent account. The county board of taxation may impose such terms and conditions for furnishing the requested information where it appears that the owner, for good cause shown, could not furnish the information within the required period of time. In making such written request for information pursuant to this section the assessor shall enclose therewith a copy of this section.
N.J.S. § 54:4-34