opinion: Justice Marshall
  delivered the opinion of the Court.
  This appeal raises the question whether notice by publication and posting provides a mortgagee of real property with adequate notice of a proceeding to sell the mortgaged property for nonpayment of taxes.
  I — I
  To secure an obligation to pay $14,000, Alfred Jean Moore executed a mortgage in favor of appellant Mennonite Board of Missions (MBM) on property in Elkhart, Ind., that Moore had purchased from MBM. The mortgage was recorded in the Elkhart County Recorder’s Office on March 1, 1973. Under the terms of the agreement, Moore was responsible for paying all of the property taxes. Without MBM’s knowledge, however, she failed to pay taxes on the property.
  Indiana law provides for the annual sale of real property on which payments of property taxes have been delinquent for 15 months or longer. Ind. Code §6-1.1-24-1 et seq. (1982). Prior to the sale, the county auditor must post notice in the county courthouse and publish notice once each week for three consecutive weeks. §6-1.1-24-3. The owner of the property is entitled to notice by certified mail to his last known address. §6-1.1-24-4. Until 1980, however, Indiana law did not provide for notice by mail or personal service to mortgagees of property that was to be sold for nonpayment of taxes.
  After the required notice is provided, the county treasurer holds a public auction at which the real property is sold to the highest bidder. § 6-1.1-24-5. The purchaser acquires a certificate of sale which constitutes a lien against the real property for the entire amount paid. §6-1.1-24-9. This lien is superior to all other liens against the property which existed at the time the certificate was issued. Ibid.
  The tax sale is followed by a 2-year redemption period during which the “owner, occupant, lienholder, or other person who has an interest in” the property may redeem the property. §6-1.1-25-1. To redeem the property an individual must pay the county treasurer a sum sufficient to cover the purchase price of the property at the tax sale and the amount of taxes and special assessments paid by the purchaser following the sale, plus an additional percentage specified in the statute. §6-1.1-25-2. The county in turn remits the payment to the purchaser of the property at the tax sale. §6-1.1-25-3.
  If no one redeems the property during the statutory redemption period, the purchaser may apply to the county auditor for a deed to the property. Before executing and delivering the deed, the county auditor must notify the former owner that he is still entitled to redeem the property. §6-1.1-25-6. No notice to the mortgagee is required. If the property is not redeemed within 30 days, the county auditor may then execute and deliver a deed for the property to the purchaser, §6-1.1-25-4, who thereby acquires “an estate in fee simple absolute, free and clear of all liens and encumbrances . ” § 6-1. l-25-4(d).
  After obtaining a deed, the purchaser may initiate an action to quiet his title to the property. § 6-1.1-25-14. The previous owner, lienholders, and others who claim to have an interest in the property may no longer redeem the property. They may defeat the title conveyed by the tax deed only by proving, inter alia, that the property had not been subject to, or assessed for, the taxes for which it was sold, that the taxes had been paid before the sale, or that the property was properly redeemed before the deed was executed. §6-1.1-25-16.
  In 1977, Elkhart County initiated proceedings to sell Moore’s property for nonpayment of taxes. The county provided notice as required under the statute: it posted and published an announcement of the tax sale and mailed notice to Moore by certified mail. MBM was not informed of the pending tax sale either by the County Auditor or by Moore. The property was sold for $1,167.75 to appellee Richard Adams on August 8, 1977. Neither Moore nor MBM appeared at the sale or took steps thereafter to redeem the property. Following the sale of her property, Moore continued to make payments each month to MBM, and as a result MBM did not realize that the property had been sold. On August 16,1979, MBM first learned of the tax sale. By then the redemption period had run and Moore still owed appellant $8,237.19.
  In November 1979, Adams filed a suit in state court seeking to quiet title to the property. In opposition to Adams’ motion for summary judgment, MBM contended that it had not received constitutionally adequate notice of the pending tax sale and of the opportunity to redeem the property following the tax sale. The trial court upheld the Indiana tax sale statute against this constitutional challenge. The Indiana Court of Appeals affirmed. 427 N. E. 2d 686 (1981). We noted probable jurisdiction, 459 U. S. 908 (1982), and we now reverse.
  II
  In Mullane v. Central Hanover Bank & Trust Co., 339 U. S. 306, 314 (1950), this Court recognized that prior to an action which will affect an interest in life, liberty, or property protected by the Due Process Clause of the Fourteenth Amendment, a State must provide “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.” Invoking this “elementary and fundamental requirement of due process,” ibid., the Court held that published notice of an action to settle the accounts of a common trust fund was not sufficient to inform beneficiaries of the trust whose names and addresses were known. The Court explained that notice by publication was not reasonably calculated to provide actual notice of the pending proceeding and was therefore inadequate to inform those who could be notified by more effective means such as personal service or mailed notice:
  “Chance alone brings to the attention of even a local resident an advertisement in small type inserted in the back pages of a newspaper, and if he makes his home outside the area of the newspaper’s normal circulation the odds that the information will never reach him are large indeed. The chance of actual notice is further reduced when, as here, the notice required does not even name those whose attention it is supposed to attract, and does not inform acquaintances who might call it to attention. In weighing its sufficiency on the basis of equivalence with actual notice, we are unable to regard this as more than a feint.” Id., at 315.
  In subsequent cases, this Court has adhered unwaveringly to the principle announced in Mullane. In Walker v. City of Hutchinson, 352 U. S. 112 (1956), for example, the Court held that notice of condemnation proceedings published in a local newspaper was an inadequate means of informing a landowner whose name was known to the city and was on the official records. Similarly, in Schroeder v. New York City, 371 U. S. 208 (1962), the Court concluded that publication in a newspaper and posted notices were inadequate to apprise a property owner of condemnation proceedings when his name and address were readily ascertainable from both deed records and tax rolls. Most recently, in Greene v. Lindsey, 456 U. S. 444 (1982), we held that posting a summons on the door of a tenant's apartment was an inadequate means of providing notice of forcible entry and detainer actions. See also Memphis Light, Gas & Water Div. v. Craft, 436 U. S. 1, 13-15 (1978); Eisen v. Carlisle & Jacquelin, 417 U. S. 156, 174-175 (1974); Bank of Marin v. England, 385 U. S. 99, 102 (1966); Covey v. Town of Somers, 351 U. S. 141, 146-147 (1956); New York City v. New York, N. H. & H. R. Co., 344 U. S. 293, 296-297 (1953).
  This case is controlled by the analysis in Mullane. To begin with, a mortgagee possesses a substantial property interest that is significantly affected by a tax sale. Under Indiana law, a mortgagee acquires a lien on the owner’s property which may be conveyed together with the mortgag- or’s personal obligation to repay the debt secured by the mortgage. Ind. Code §32-8-11-7 (1982). A mortgagee’s security interest generally has priority over subsequent claims or liens attaching to the property, and a purchase-money mortgage takes precedence over virtually all other claims or liens including those which antedate the execution of the mortgage. § 32-8-11-4. The tax sale immediately and drastically diminishes the value of this security interest by granting the tax-sale purchaser a lien with priority over that of all other creditors. Ultimately, the tax sale may result in the complete nullification of the mortgagee’s interest, since the purchaser acquires title free of all liens and other encumbrances at the conclusion of the redemption period.
  Since a mortgagee clearly has a legally protected property interest, he is entitled to notice reasonably calculated to apprise him of a pending tax sale. Cf. Wiswall v. Sampson, 14 How. 52, 67 (1853). When the mortgagee is identified in a mortgage that is publicly recorded, constructive notice by publication must be supplemented by notice mailed to the mortgagee’s last known available address, or by personal service. But unless the mortgagee is not reasonably identifiable, constructive notice alone does not satisfy the mandate of Mullane,
  Neither notice by publication and posting, nor mailed notice to the property owner, are means “such as one desirous of actually informing the [mortgagee] might reasonably adopt to accomplish it.” Mullane, 339 U. S., at 315. Because they are designed primarily to attract prospective purchasers to the tax sale, publication and posting are unlikely to reach those who, although they have an interest in the property, do not make special efforts to keep abreast of such notices. Walker v. City of Hutchinson, supra, at 116; New York City v. New York, N. H. & H. R. Co., supra, at 296; Mullane, supra, at 315. Notice to the property owner, who is not in privity with his creditor and who has failed to take steps necessary to preserve his own property interest, also cannot be expected to lead to actual notice to the mortgagee. Cf. Nelson v. New York City, 352 U. S. 103, 107-109 (1956). The county’s use of these less reliable forms of notice is not reasonable where, as here, “an inexpensive and efficient mechanism such as mail service is available.” Greene v. Lindsey, supra, at 455.
  Personal service or mailed notice is required even though sophisticated creditors have means at their disposal to discover whether property taxes have not been paid and whether tax-sale proceedings are therefore likely to be initiated. In the first place, a mortgage need not involve a complex commercial transaction among knowledgeable parties, and it may well be the least sophisticated creditor whose security interest is threatened by a tax sale. More importantly, a party’s ability to take steps to safeguard its interests does not relieve the State of its constitutional obligation. It is true that particularly extensive efforts to provide notice may often be required when the State is aware of a party’s inexperience or incompetence. See, e. g., Memphis Light, Gas & Water Div. v. Craft, supra, at 13-15; Covey v. Town of Somers, supra. But it does not follow that the State may forgo even the relatively modest administrative burden of providing notice by mail to parties who are particularly resourceful. Cf. New York City v. New York, N. H. & H. R. Co., 344 U. S., at 297. Notice by mail or other means as certain to ensure actual notice is a minimum constitutional precondition to a proceeding which will adversely affect the liberty or property interests of any party, whether unlettered or well versed in commercial practice, if its name and address are reasonably ascertainable. Furthermore, a mortgagee’s knowledge of delinquency in the payment of taxes is not equivalent to notice that a tax sale is pending. The latter “was the information which the [county] was constitutionally obliged ... to give personally to the appellant — an obligation which the mailing of a single letter would have discharged.” Schroeder v. New York City, 371 U. S., at 214.
  We therefore conclude that the manner of notice provided to appellant did not meet the requirements of the Due Process Clause of the Fourteenth Amendment. Accordingly, the judgment of the Indiana Court of Appeals is reversed, and the cause is remanded for further proceedings not inconsistent with this opinion.
  It is so ordered.
  Because a mortgagee has no title to the mortgaged property under Indiana law, the mortgagee is not considered an “owner” for purposes of § 6-1.1-24-4. First Savings & Loan Assn. of Central Indiana v. Furnish, 174 Ind. App. 265, 272, n. 14, 367 N. E. 2d 596, 600, n. 14 (1977).
  Indiana Code §6-1.1-24-4.2 (1982), added in 1980, provides for notice by certified mail to any mortgagee of real property which is subject to tax sale proceedings, if the mortgagee has annually requested such notice and has agreed to pay a fee, not to exceed $10, to cover the cost of sending notice. Because the events in question in this case occurred before the 1980 amendment, the constitutionality of the amendment is not before us.
  The decision in Mullane rejected one of the premises underlying this Court’s previous decisions concerning the requirements of notice in judicial proceedings: that due process rights may vary depending on whether actions are in rem or in personam. 339 U. S., at 312. See Shaffer v. Heitner, 433 U. S. 186, 206 (1977). Traditionally, when a state court based its jurisdiction upon its authority over the defendant’s person, personal service was considered essential for the court to bind individuals who did not submit to its jurisdiction. See, e. g., Hamilton v. Brown, 161 U. S. 256, 275 (1896); Arndt v. Griggs, 134 U. S. 316, 320 (1890); Pennoyer v. Neff, 95 U. S. 714, 726, 733-734 (1878) (“[D]ue process of law would require appearance or personal service before the defendant could be personally bound by any judgment rendered”). In Hess v. Pawloski, 274 U. S. 352 (1927), the Court recognized for the first time that service by registered mail, in place of personal service, may satisfy the requirements of due process. Constructive notice was never deemed sufficient to bind an individual in an action in personam.
  In contrast, in in rem or quasi in rem proceedings in which jurisdiction was based on the court’s power over property within its territory, see generally Shaffer v. Heitner, supra, at 196-205, constructive notice to nonresidents was traditionally understood to satisfy the requirements of due process. In order to settle questions of title to property within its territory, a state court was generally required to proceed by an in rem action since the court could not otherwise bind nonresidents. At one time constructive service was considered the only means of notifying nonresidents since it was believed that “[pjrocess from the tribunals of one State cannot run into another State.” Pennoyer v. Neff, supra, at 727. See Ballard v. Hunter, 204 U. S. 241, 255 (1907). As a result, the nonresident acquired the duty “to take measures that in some way he shall be represented when his property is called into requisition.” Id., at 262. If he “fail[ed] to get notice by the ordinary publications which have been usually required in such cases, it [was] his misfortune.” Ibid.
  Rarely was a corresponding duty imposed on interested parties who resided within the State and whose identities were reasonably ascertainable. Even in actions in rem, such individuals were generally provided personal service. See, e. g., Arndt v. Griggs, supra, at 326-327. Where the identity of interested residents could not be ascertained after a reasonably diligent inquiry, however, their interests in property could be affected by a proceeding in rem as long as constructive notice was provided. See Hamilton v. Brown, supra, at 275; American Land Co. v. Zeiss, 219 U. S. 47, 61-62, 65-66 (1911).
  Beginning with Mullane, this Court has recognized, contrary to the earlier line of cases, that “an adverse judgment in rem directly affects the property owner by divesting him of his rights in the property before the court.” Shaffer v. Heitner, supra, at 206. In rejecting the traditional justification for distinguishing between residents and nonresidents and between in rem and in personam actions, the Court has not left all interested claimants to the vagaries of indirect notice. Our cases have required the State to make efforts to provide actual notice to all interested parties comparable to the efforts that were previously required only in in personam actions. See infra, this page.
  In this case, the mortgage on file with the County Recorder identified the mortgagee only as “MENNONITE BOARD OF MISSIONS a corporation, of Wayne County, in the State of Ohio.” We assume that the mortgagee’s address could have been ascertained by reasonably diligent efforts. See Mullane v. Central Hanover Bank & Trust Co., 339 U. S., at 317. Simply mailing a letter to “Mennonite Board of Missions, Wayne County, Ohio,” quite likely would have provided actual notice, given “the well-known skill of postal officials and employés in making proper delivery of letters defectively addressed.” Grannis v. Ordean, 234 U. S. 385, 397-398 (1914). We do not suggest, however, that a governmental body is required to undertake extraordinary efforts to discover the identity and whereabouts of a mortgagee whose identity is not in the public record.
  Indeed, notice by mail to the mortgagee may ultimately relieve the county of a more substantial administrative burden if the mortgagee arranges for payment of the delinquent taxes prior to the tax sale.
  This appeal also presents the question whether, before the County Auditor executes and delivers a deed to the tax-sale purchaser, the mortgagee is constitutionally entitled to notice of its right to redeem the property. Cf. Griffin v. Griffin, 327 U. S. 220, 229 (1946). Because we conclude that the failure to give adequate notice of the tax-sale proceeding deprived appellant of due process of law, we need not reach this question.