N.J. Stat. § 54:4-2.49
If any taxpayer shall refuse or neglect to file a return as required by the preceding section, the assessor shall value the taxable personal property of such taxpayer at such amount as he may, from any information in his possession or available to him, reasonably determine to be the taxable value at which such property is assessable. Any taxpayer who fails or neglects to file a return within the time required shall be assessed a penalty of $100.00 for each day of such delinquency, but not in excess of the greater of $100.00 or 25% of the tax. All penalties shall be added to and become part of the tax and shall be enforceable and collectible in the same manner as the tax or pursuant to the penalty enforcement law (chapter 58 of Title 2A of the New Jersey Statutes) in a summary manner. Such penalties shall be assessed by the assessor and be payable to and recoverable by the tax collector of the taxing district. The assessor, upon request made on or before the last date for filing any return as fixed by law, may extend the time to file such return to a date not later than the end of a 2-month period next following such last date for filing, for good cause shown.
N.J.S. § 54:4-2.49