N.J. Stat. § 19:63-8
Upon receipt of a request for a mail-in ballot, the county clerk shall, with the cooperation of the commissioner of registration, cause the signature of the applicant to be compared with the signature of the person appearing on the permanent registration form, or the digitalized image of the voter's signature stored in the Statewide voter registration system, to determine from such examination, and any other available information, if the applicant is a voter qualified to cast a ballot in the election in which the voter wants to vote, and determine in case of a primary election the political party primary in which the voter is entitled to vote. The commissioner of registration, or the superintendent of elections in counties having a superintendent of elections may, at the request of the county clerk, investigate any application or request for a mail-in ballot.
If, after such examination, the county clerk is satisfied that the applicant is entitled to a ballot, the clerk shall mark on the application "Approved." If, after such examination the county clerk determines that the applicant is not entitled to a ballot, the clerk shall mark on the application "Disapproved" and shall so notify the applicant, stating the reason therefor, as required by section 5 of P.L. 2004, c. 88(C.19:61-5). Notification to the applicant shall be made in writing within 24 hours of the determination of disapproval and shall state the specific reason, or reasons, for the disapproval and inform the applicant of the opportunity to challenge the disapproval by contacting the county clerk's office. The county clerk shall provide every disapproved applicant with the opportunity to (1) submit evidence either in person or via fax, postal mail or electronic mail, (2) submit a voter registration application to update signature or change name, address, or party affiliation, (3) submit a new application to vote by mail, or (4) in the case of an application disapproved for a reason related to signature verification, sign an affidavit in the presence of the county clerk, or designee, after presenting current and valid photo identification.
N.J.S. § 19:63-8