Last amended March 8, 2011 · Current through June 18, 2026 · Last verified July 7, 2026
In one sentenceRule 4:26-5 supplies the designations for naming unknown defendants in actions affecting specific property or a res — including unknown spouses, heirs, successors, and unknown owners or claimants — once the required affidavit of inquiry shows their identities could not be ascertained.
(a)Applicability. R. 4:26-5 applies only to actions governed by R. 4:4-5 (actions affecting specific property or a res).
(b)Description of Unknown Defendants. When it shall appear by the affidavit of inquiry required by R. 4:4-5(a)(3) that the affiant has been unable to ascertain whether or not any person who is a proper party defendant is married, or, if married, the given name of the wife of such male defendant or the surname and either the given name or initial thereof of the husband of such female defendant, or that the affiant has been unable to ascertain whether or not any person who is a proper party defendant is still the owner of the specific property or res or any interest therein, and has been unable to ascertain the names and residences of any of the person’s successors in right, title and interest in the same, or that the affiant has been unable to ascertain whether or not such person is still alive, or if such person is known or believed to be dead, that the affiant has been unable, in either case, to ascertain the names and residences of such person’s heirs, devisees or personal representatives or his, hers, their, or any of their, successors in right, title or interest in the property or res or interest therein, or of such of them as may be proper parties defendant in the action, any such person or unknown person or persons may be made a party defendant by such of the following designations as may be appropriate:
(1)As to any such male person and such wife, if he has any, by designating such male person by his proper given name and surname, as it appears of record or otherwise, and by designating such wife by the given name and surname of such male person, as it so appears, with “Mrs.” prefixed thereto; or
(2)As to any such female person and such husband, if she has any, by designating such female person by her proper given name and surname, as it appears, of record or otherwise, and by designating such husband either
(i)By the name of such female, as it so appears, as “Mr. ...................... , husband of ......................” using such surname of such female person in the first blank and such given name and such surname of such female person in the second blank; or
(ii)By the name “John Doe, husband of ......................, said name of John Doe being fictitious,” using the given name and surname of such female person in the blank; or
(3)As to any such person, whether such person is still alive or whether it is not known whether such person is alive or dead, or if such person is known or is believed to be dead, and as to any such person’s unknown heirs, devisees or personal representatives or his, hers, their, or any of their successors in right, title and interest in such specific property or interest therein or such res, thus: “ ...................... , his or her heirs, devisees and personal representatives and his, hers, their, or any of their, successors in right, title and interest,” using the name of such person in the blank.
(c)Designation of Unknown Owner or Claimant. When it shall appear by the affidavit of inquiry required by R. 4:4-5(a)(3) that the affiant has been unable to ascertain the name or names of any unknown owner or claimant, such unknown owner or claimant may be made a party defendant and shall be sufficiently described for all purposes including service of process by the designation “Unknown Owner (or Unknown Claimant), his or her heirs, devisees and personal representatives, and his, hers, their or any of their successors in right, title and interest.” Where title to real property or an interest therein or a lien or encumbrance thereon is involved, the inquiry shall include, and the affidavit of inquiry shall recite, reasonable diligence in searching the title, or having it searched, for a period of 60 years immediately prior to the commencement of the action. If such search does not disclose the name of a person who it is alleged or claimed owns the same or a part thereof, or some interest therein, or holds a lien or encumbrance thereon, the action may proceed against unknown owners or unknown claimants.
(d)Other Designations. Where the manner of joining or designating an unknown defendant is not specifically fixed by this rule, the court may on motion with or without notice order the action to proceed against such defendant by fixing the manner and the designation by which the person shall be made a party defendant, adding a description of the person’s interest in the action and stating so much of the person’s name as is known.
(e)Effect of Designation. The person or persons designated as set forth in R. 4:26-5 shall be deemed as a party defendant to the action and as sufficiently described for all purposes, including service of process.
Amendment History
New Jersey publishes each rule’s amendment record in a “History” note beneath the rule. It is reproduced verbatim below; the “R.R.” citations refer to the former Revised Rules numbering the current rules replaced.
Source - R.R. 4:30-4(a) (b) (first sentence) (c) (d) (e); introductory paragraph and paragraphs (b), (c) and (d); amended July 13, 1994 to be effective September 1, 1994; paragraph (c); amended July 23, 2010 to be effective September 1, 2010; paragraph (b); amended March 8, 2011 to be effective immediately.
Plain-English Summary
In actions affecting specific property, the persons with an interest are sometimes unknown — an unnamed spouse, an heir, or a successor in title. This rule, which applies only to the in rem actions governed by Rule 4:4-5, provides standardized designations for naming them once the affidavit of inquiry shows their identities or marital status could not be ascertained. It prescribes exact forms for an unknown spouse, for heirs, devisees, and personal representatives, and for successors in interest.
It also handles wholly unknown owners and claimants. When the affiant cannot ascertain a name, the person may be joined as an “Unknown Owner” or “Unknown Claimant,” and where real property or a lien is involved the inquiry must include a 60-year title search. A person so designated is deemed a party defendant, sufficiently described for all purposes including service of process, and the court may fix another designation where the rule does not.
Frequently Asked Questions
How do you name an unknown owner in a property action?
Once the affidavit of inquiry shows the name could not be ascertained, the person may be joined as “Unknown Owner” or “Unknown Claimant” with the rule’s prescribed heirs-and-successors language. For real property, the inquiry must include a 60-year title search.
Source & verification. The rule text and amendment history are reproduced verbatim from the
official New Jersey Rules of Court (N.J. Ct. R. 4:26-5). Prescribed by the Supreme Court of New Jersey (N.J. Const. art. VI, § 2, ¶ 3). The plain-English summary is original and written by us. Last verified July 7, 2026. ·
Official source
Also known as:unknown defendantsin rem unknown partiesunknown ownerunknown claimantquiet title partiesaffidavit of inquiry