N.J. Stat. § 2A:44-19.3
In the event that payment is not made of the agreed charges or the reasonable value thereof for the work, services, storage, materials or supplies within 90 days after any of the goods were to be delivered or to be available to the customer, the goods may be sold at a public or private sale to pay the agreed or reasonable charges together with the cost of notifying the customer. The person to whom the charges are payable and owing shall, at least 30 days prior to the sale, give notice of the time and place of the sale to the customer. The notice shall be mailed to the customer at his last known address by certified mail, return receipt requested. Where the address of the customer is unknown, the posting of a notice of the sale in a prominent place in a public portion of the premises of the person required to give the notice shall constitute notice.
N.J.S. § 2A:44-19.3