N.J. Stat. Ann. § 46:30B-106

Unenforceable agreements. All agreements to pay compensation to locate, deliver, recover, or assist in the recovery of property reported under this chapter, made within 24 months after the date that the property is paid or delivered to the administrator, are void and unenforceable. Agreements entered into any time after such 24-month period are valid only if the fee or compensation agreed upon is not more than 20% of the value of the property recovered, the agreement is in writing, signed by the apparent owner, and clearly sets forth the nature and value of the property and the value of the apparent owner's share after the fee or compensation has been deducted. Agreements entered into before the property was presumed abandoned are valid only if the fee or compensation agreed upon is not more than 35% of the value, the agreement is in writing, signed by the apparent owner, and clearly sets forth the nature and value of the property and the value of the apparent owner's share after the fee or compensation has been deducted. However, nothing in this section shall be construed to prevent an owner from asserting at any time that an agreement to locate property is based upon an excessive or unjust consideration.