{¶ 1} The Montgomery County Children Services Board appeals from a decision of the Second District Court of Appeals, which reversed the trial court order granting the board permanent custody of Shawn Thompkins.
{¶ 2} The single issue we confront concerns whether the board exercised reasonable diligence in attempting to serve Shawn’s father, Iler Crawford, by certified mail, which the postal service returned marked “Attempted Not Known,” or whether the board had a legal obligation to follow up with ordinary mail, as Civ.R. 4.6(D) allows for certified mail returned “Unclaimed,” before service by publication would be deemed sufficient. Stated differently, did the board exercise reasonable diligence in attempting to serve Crawford even though the board did not attempt service by ordinary mail at an address from which the certified mail addressed to Crawford was returned marked “Attempted Not Known”? The answer is yes. Therefore, we reverse the judgment of the court of appeals.
I
{¶ 3} The parties do not dispute the relevant facts. A judgment entry of paternity established that appellee, Iler Crawford, is the father of the minor child, Shawn Thompkins. The appellant, Montgomery County Children Services Board, first sought permanent custody of Thompkins in October 2002. The board discovered two possible addresses for Crawford — one in Columbus and one in Dayton. Crawford’s mother accepted service of process on his behalf at the Dayton address. However, because the trial court did not adjudicate the complaint for permanent custody before the 90-day period set forth in R.C. 2151.35(B)(1) expired, the board filed a new complaint for permanent custody in February 2003.
*410{¶ 4} The board attempted to personally serve Crawford at the Dayton address in March 2003. That attempt failed, and the process server reported that Crawford had not resided at the Dayton address for almost one year. Pursuant to Civ.R. 4.4(A)(1), the board filed an affidavit for service by publication asserting that Crawford could not be served by summons because his address was unknown to the board and could not be ascertained with reasonable diligence. Thereafter, a notice of the upcoming hearing appeared in the Daily Court Reporter, a newspaper of general circulation in Montgomery County.
{¶ 5} After publication of the notice and before the permanent-custody hearing commenced, the board attempted to serve Crawford by certified mail at the Columbus address. The postmaster returned the certified letter to the Montgomery County Juvenile Court bearing a stamp listing five possible reasons for mail to be returned: “Attempted Not Known,” “Insufficient Address,” “No Such Number/Street,” “Not Deliverable as Addressed — Unable to Forward,” and “Other.” A mark appeared next to “Attempted Not Known.”
{¶ 6} Counsel appointed to represent Crawford appeared at the hearing on the complaint for permanent custody and claimed that the trial court lacked personal jurisdiction over Crawford because the board had failed to perfect service upon him. The magistrate ruled that the board had properly served Crawford by publication and proceeded with the custody hearing. In July 2003, the magistrate determined that Thompkins was a dependent child and awarded permanent custody to the board. Crawford’s counsel objected to the court’s exercise of personal jurisdiction over Crawford. However, the trial court overruled the objection and adopted the magistrate’s decision. Crawford’s counsel appealed the trial court’s judgment to the Second District Court of Appeals. Appellate counsel informed the court that he could not locate his client. Crawford’s counsel filed an Anders brief, see Anders v. California (1967), 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493, in which he noted a potential issue involving a defect in service and resultant lack of personal jurisdiction but concluded that the issue lacked merit. The appellate court determined that the service-of-proeess issue had sufficient merit to prevent the appeal from being wholly frivolous. Consequently, the court appointed new counsel, who filed a brief raising this assignment of error.
{¶ 7} Reviewing the merits, the court of appeals noted that when a children services board seeks to terminate parental rights, Juv.R. 16 requires the board to exercise reasonable diligence in its effort to serve the parents with process and that reasonable diligence requires attempts to serve the parents in accordance with Civ.R. 4(A), (C), and (D), 4.1, 4.2, 4.3, 4.5, and 4.6 before resorting to service by publication.
*411{¶ 8} The appellate court then determined that the “Attempted Not Known” notation on the certified mail envelope returned to the Montgomery County Juvenile Court was the equivalent of an envelope returned “Unclaimed.” This triggered the application of Civ.R. 4.6(D), which allows a party to request service by ordinary mail. Because the board did not request service by ordinary mail, the appellate court concluded that it did not exercise due diligence in attempting to serve Crawford before resorting to service by publication. Therefore, the appellate court held that service by publication was insufficient and the trial court lacked personal jurisdiction over Crawford.
{¶ 9} We accepted the state’s discretionary appeal.
{¶ 10} The right of a parent to the custody of his or her child is one of the oldest fundamental liberty interests recognized by American courts. Troxel v. Granville (2000), 530 U.S. 57, 65-66, 120 S.Ct. 2054, 147 L.Ed.2d 49. See also In re Adoption of Walters, 112 Ohio St.3d 315, 2007-Ohio-7, 859 N.E.2d 545, ¶ 18, citing In re Hayes (1997), 79 Ohio St.3d 46, 48, 679 N.E.2d 680 (the right to raise one’s child is an essential and basic civil right); In re Adoption of Pushcar, 110 Ohio St.3d 332, 2006-Ohio-4572, 853 N.E.2d 647, ¶ 11, citing Santosky v. Kramer (1982), 455 U.S. 745, 753, 102 S.Ct. 1388, 71 L.Ed.2d 599 (“natural parents have a fundamental right to the care and custody of their children”).
{¶ 11} Moreover, this court has noted that “[p’jermanent termination of parental rights has been described as ‘the family law equivalent of the death penalty in a criminal case.’ * * * Therefore, parents ‘must be afforded every procedural and substantive protection the law allows.’ ” Hayes, 79 Ohio St.3d at 48, 679 N.E.2d 680, quoting In re Smith (1991), 77 Ohio App.3d 1, 16, 601 N.E.2d 45.
{¶ 12} The Due Process Clause of the Fifth Amendment to the United States Constitution, as applicable to the states through the Fourteenth Amendment, provides: “No person shall * * * be deprived of life, liberty, or property, without due process of law.” But “[f]or all its consequence, ‘due process’ has never been, and perhaps can never be, precisely defined. * * * Rather, the phrase expresses the requirement of ‘fundamental fairness,’ a requirement whose meaning can be as opaque as its importance is lofty. Applying the Due Process Clause is therefore an uncertain enterprise which must discover what ‘fundamental fairness’ consists of in a particular situation by first considering any relevant precedents and then by assessing the several interests that are at stake.” Lassiter v. Dept. of Social Servs. of Durham Cty., North Carolina (1981), 452 U.S. 18, 24-25, 101 S.Ct. 2153, 68 L.Ed.2d 640.
{¶ 13} Our courts have long recognized that due process requires both notice and an opportunity to be heard. See, e.g., Hagar v. Reclamation Dist. No. 108 (1884), 111 U.S. 701, 708, 4 S.Ct. 663, 28 L.Ed. 569; Caldwell v. Carthage (1892), 49 Ohio St. 334, 348, 31 N.E. 602. In Mullane v. Cent. Hanover Bank & Trust *412Co. (1950), 339 U.S. 306, 70 S.Ct. 652, 94 L.Ed. 865, the United States Supreme Court enunciated the standard for determining whether service of process comports with due process, holding: “An elementary and fundamental requirement of due process in any proceeding which is to be accorded finality is notice reasonably calculated, under all the circumstances, to apprise interested parties of the pendency of the action and afford them an opportunity to present their objections.” Id. at 314, 70 S.Ct. 652, 94 L.Ed. 865.
{¶ 14} In accordance with this requirement, the government must attempt to provide actual notice to interested parties if it seeks to deprive them of a protected liberty or property interest. Dusenbery v. United States (2002), 534 U.S. 161, 170, 122 S.Ct. 694, 151 L.Ed.2d 597. However, due process does not require that an interested party receive actual notice. Id. Moreover, while “[t]he means employed must be such as one desirous of actually informing the absentee might reasonably adopt to accomplish it,” Mullane, 339 U.S. at 315, 70 S.Ct. 652, 94 L.Ed. 865, due process does not require “heroic efforts” to ensure the notice’s delivery, Dusenbery, 534 U.S. at 170, 122 S.Ct. 694, 151 L.Ed.2d 597.
{¶ 15} Here, we must determine whether the board exercised reasonable diligence in attempting to notify Crawford that his parental rights were subject to termination, so that its efforts comport with our rules for the service of process and with due process requirements. Crawford did not receive actual notice of the termination proceeding; he was not aware of the case that could, and did, terminate his constitutionally protected parental rights. Indeed, it appears that Crawford remains unaware of the lengthy proceedings conducted to preserve his parental rights, as even his own court-appointed attorneys have been unable to locate him during the pendency of this action.
{¶ 16} A number of rules and statutes govern the service of process in Ohio. Juv.R. 16(A) states that a “summons shall be served as provided in Civil Rules 4(A), (C) and (D), 4.1, 4.2, 4.3, 4.5 and 4.6.” The rule further provides that “when the residence of a party is unknown and cannot be ascertained with reasonable diligence, service shall be made by publication.”
{¶ 17} Civ.R. 4.6(D) provides: “If a certified or express mail envelope is returned with an endorsement showing that the envelope was unclaimed, the clerk shall forthwith notify, by mail, the attorney of record or, if there is no attorney of record, the party at whose instance process was issued. If the attorney, or serving party, after notification by the clerk, files with the clerk a written request for ordinary mail service, the clerk shall send by ordinary mail a copy of the summons and complaint or other document to be served to the defendant at the address set forth in the caption, or at the address set forth in written instructions furnished to the clerk. * * * Service shall be deemed complete when the fact of mailing is entered of record, provided that the ordinary *413mail envelope is not returned by the postal authorities with an endorsement showing failure of delivery. If the ordinary mail envelope is returned undelivered, the clerk shall forthwith notify the attorney, or serving party, by mail.”
{¶ 18} Further, R.C. 2151.29 states:
{¶ 19} “Service of summons, notices, and subpoenas * * * shall be made by delivering a copy to the person summoned, notified, or subpoenaed, or by leaving a copy at the person’s usual place of residence. If the juvenile judge is satisfied that such service is impracticable, the juvenile judge may order service by registered or certified mail. * * *
{¶20} “Whenever it appears by affidavit that after reasonable effort the person to be served with summons cannot be found or the person’s post-office address ascertained, * * * the clerk shall publish such summons once in a newspaper of general circulation throughout the county.”
{¶ 21} Pursuant to Civ.R. 4.6(D), when service is attempted by certified mail, as it was in this ease, and the certified mail “is returned with an endorsement showing that the envelope was unclaimed,” the serving party must be notified, and may then request that service be attempted by ordinary mail.
{¶ 22} Here, the postal service returned the certified mail marked “Attempted Not Known.” The United States Postal Service, Domestic Mail Manual, Section 507, Exhibit 1.4.1, available at http://pe.usps.gov/text/dmm300/507.htm, provides that the endorsement “Unclaimed” means that the reason for nondelivery was that the “[ajddressee abandoned or failed to call for mail,” while the endorsement “Attempted — Not Known” means “[djelivery attempted, addressee not known at place of address.”
{¶ 23} When a postal return reads “Attempted Not Known,” no purpose would be served by a follow-up ordinary mail letter sent to the same address. The “Unclaimed” designation implies that the person may in fact reside or receive mail at the designated address but for whatever reason has chosen not to sign for the certified mail. In that situation, a follow-up communication by ordinary mail is reasonably calculated to provide the interested party with notice and an opportunity to be heard. Such a communication, not returned, bears a strong inference that the intended recipient received the letter. This is not so, however, with ordinary mail following the return of a certified letter with the endorsement “Attempted Not Known.” The inference then is that the intended recipient does not reside or receive mail at the designated address and is not known to the residents there. A follow-up letter in these circumstances would not permit a similar inference of receipt.
{¶ 24} In this case, the board complied with the rules by attempting to personally serve Crawford at the Dayton address, by attempting to serve him by *414certified mail at the Columbus address, and by publishing a notice in the Daily Court Reporter in Montgomery County. Neither Civ.R. 4.6(D) nor the Due Process Clause required the board to attempt service at the Columbus address by ordinary mail. The returned certified letter, endorsed “Attempted Not Known,” clearly demonstrated that Crawford did not reside and was not known at the Columbus address. Therefore, any ordinary mail addressed to him at that address could not be reasonably calculated to give him notice and an opportunity to be heard at the permanent-custody proceeding.
{¶ 25} In considering what constitutes reasonable diligence under Civ.R. 4.4(A), this court has stated: “Black’s Law Dictionary (5 Ed.1979), at 412, defines ‘reasonable diligence’ as ‘[a] fair, proper and due degree of care and activity, measured with reference to the particular circumstances; such diligence, care, or attention as might be expected from a man of ordinary prudence and activity.’ As indicated by the above definition, what constitutes reasonable diligence will depend on the facts and circumstances of each particular case.” Sizemore v. Smith (1983), 6 Ohio St.3d 330, 332, 6 OBR 387, 453 N.E.2d 632. We declared that “[rjeasonable diligence requires taking steps which an individual of ordinary prudence would reasonably expect to be successful in locating a defendant’s address.” Id.
{¶ 26} In Sizemore, we recognized that steps taken in the effort to exercise reasonable diligence might include consulting a city directory, examining government records, or making inquiries of possible acquaintances of the person sought. Id. But we cautioned that “[t]hese examples do not constitute a mandatory checklist. Rather, they exemplify that reasonable diligence requires [the use of] common and readily available sources” in the search. Id.
{¶ 27} In support of its request for service by publication, the board submitted a “reasonable diligence” affidavit to the trial court on March 13, 2003. That affidavit stated that Crawford’s residence was unknown to the affiant and that his last known addresses were in Columbus, where the board later attempted certified mail service, and his mother’s address in Dayton.
{¶ 28} The affidavit stated that the board conducted a “diligent search” by (1) checking criminal databases including the CRIS-E Prison Locator, the Montgomery County Jail, and the Ohio Defender Database; (2) sending letters to the Columbus address, which the postal service later returned; (3) attempting to obtain residential service at the Dayton home of Crawford’s mother, which had been successful in the prior case; and (4) attempting to contact family members at the mother’s address. The affidavit further stated that the board “knows of no other addresses for the legal father,” and concluded that “[t]he residence of the legal father cannot be ascertained with reasonable diligence and service should be made by publication as provided by law.”
*415{¶ 29} Because we determine that neither Civ.R. 4.6(D) nor the Due Process Clause requires ordinary mail service when the postal authorities return certified mail with the endorsement “Attempted Not Known” before a party attempts service by publication, and inasmuch as no party has otherwise challenged the board’s averment that it exercised reasonable diligence in attempting to ascertain Crawford’s address, we conclude that the board exercised reasonable diligence in attempting to serve Crawford. Accordingly, we reverse the judgment of the court of appeals.
Judgment reversed.
Lundberg Stratton, Lanzinger, and Cupp, JJ., concur. Moyer, C.J., and Pfeifer and O’Connor, JJ., concur in part and dissent in part.