E. GRADY JOLLY, Circuit Judge:

During the Bolshevik Revolution of 1918, the Soviet government expropriated a piano factory and mansion owned by the Magness family in St. Petersburg, Russia. In 1994, the appellees, descendants of the Magness family, believed that changes in the laws of the Russian Federation may now authorize the recovery of their property. The Magness descendants met with Russian officials in St. Petersburg in an unsuccessful attempt to regain the real estate. This suit followed and a default judgment was entered against the Russian defendants in the amount of $234 million plus interest.

In this appeal we are called upon to interpret the service of process provisions of the Foreign Sovereign Immunities Act ("FSIA"), 28 U.S.C. § 1608(a-b), which outlines the methods for serving process upon foreign entities. Specifically, we must determine whether those provisions demand strict compliance therewith, or whether either of these provisions can be satisfied by some form of substantial compliance. In keeping with the plain language of the FSIA, we conclude that Congress intended to require strict compliance with section 1608(a) as to service upon foreign states and their political subdivisions. However, we also hold that substantial compliance — that is, actual notice of the suit and the consequences thereof — can be sufficient to satisfy the requirements of section 1608(b) as to service upon an agency or instrumentality of a foreign state. In conclusion, we vacate the default judgment and remand to allow proper service on the defendants.

I

We turn first to the procedural history of this case. In July 1997, the Magness descendants filed this suit in the Southern District of Texas, seeking a TRO that would prevent a traveling exhibit of Russian Romanov family jewels, then on display in Houston, from leaving the jurisdiction. The named defendants included the Russian Federation, the Russian Ministry of Culture, the Russian State Diamond Fund, and the Cultural Foundation sponsoring the exhibition. The suit alleged that the defendants had nationalized the Magness family property in 1918 and further had expropriated several antique pianos owned by the plaintiffs in the 1990s. The Russian Federation obtained United States counsel, who represented its interest at the TRO hearing. The court denied the TRO request.

After a year-long dormancy, in August 1998 the district court ordered the Magness descendants to serve the summons and complaint on the defendants, and to do so before September 1, 1998. They attempted to serve the defendants in several ways. They first served the attorneys who represented the Russian Federation at the TRO hearing. In addition, they served the Texas Secretary of State, with instructions that the Secretary forward the summons and complaint to "the Russian Federation c/o Boris Yeltsin and the Russian Ministry of Culture/Russian State Diamond Fund c/o Deputy Minister of Culture Mikhail Schvidkoy." The Magness descendants also forwarded the summons and complaint to the Director of Special Consular Affairs at the State Department, with instructions to serve all defendants through diplomatic channels. Finally, the Magness descendants purported to serve process by sending the summons and complaint directly to the Russian Deputy Minister of Culture in Moscow.

On November 13, 1998, the State Department informed the Magness descendants that it could not serve the defendants because of several procedural errors. On November 19, 1998, the Magness descendants filed a motion for a default judgment. The court held a hearing on the motion the following day, during which the Magness descendants submitted evidence that they had served the defendants by the methods previously described. The court determined that the defendants had been properly served and entered a default judgment. The court approved the Magness descendants' proposed findings of facts and conclusions of law on June 8, 1999, and entered a final judgment against the defendants. See Magness v. Russian Federation, 54 F.Supp.2d 700 (S.D.Tex. 1999).

In October 1999, the defendants retained United States counsel in an attempt to vacate the default judgment under Rule 60. On January 12, 2000, the district court denied the motion, ruling that the Magness descendants had "substantially complied" with the service of process requirements of the FSIA and provided sufficient notice of the suit to the defendants. This appeal followed.

II

A district court's denial of a motion to vacate under Rule 60 is reviewed for abuse of discretion. See CJC Holdings v. Wright Lato, Inc., 979 F.2d 60, 63 (5th Cir. 1992). Because of the seriousness of a default judgment, "even a slight abuse [of discretion] may justify reversal." Seven Elves, Inc. v. Eskenazi, 635 F.2d 396, 402 (5th Cir. 1981).

The FSIA outlines specific provisions for service of process upon foreign governments and agencies in 28 U.S.C. § 1608. The Magness descendants acknowledge that they failed strictly to comply with the service provisions of the FSIA. The provisions for service under section 1608 are hierarchical, such that a plaintiff must attempt the methods of service in the order they are laid out in the statute. Regarding the Russian Federation and the Russian Ministry of Culture under section 1608(a), they must first be served in accordance with any special arrangement between the parties or in accordance with an applicable international convention. See 28 U.S.C. § 1608(a)(1-2). Given that there was no special arrangement or international convention governing service here, the Magness descendants are required to have attempted service on the head of the Russian Ministry of Foreign Affairs. See 28 U.S.C. § 1608(a)(3). Finally, if service could not be made through the Ministry of Foreign Affairs within thirty days, they could resort to service through the State Department. See 28 U.S.C. § 1608(a)(4).

Instead of asking the clerk of the district court to send the summons and notice of suit by return receipt mail to the head of the Russian foreign ministry under section 1608(a)(3), the Magness descendants sent their complaint to the Texas Secretary of State for forwarding to Boris Yeltsin, and sent the complaint directly to the Russian Deputy Minister of Culture. Thus, the FSIA was not strictly complied with as to the Russian Federation and Ministry of Culture.

As to the Russian State Diamond Fund, section 1608(b) (applicable to instrumentalities of a foreign state) was similarly not strictly followed. A plaintiff must first attempt service in accordance with any special arrangement between the parties. See 28 U.S.C. § 1608(b)(1). Next, a plaintiff may serve through an authorized agent in the United States or according to an applicable international convention. See 28 U.S.C. § 1608(b)(2). If no such agent or convention exists, as was the case here, a plaintiff may serve papers via a letter rogatory, through the clerk of the court, or as directed by the court, if these methods are "reasonably calculated to give actual notice." See 28 U.S.C. § 1608(b)(3). Instead of following the statute, the Magness descendants forwarded a copy of their papers to the State Department and the Texas Secretary of State for service upon the Fund. Thus, the requirements of section 1608(b) were not strictly followed as to the Russian State Diamond Fund.

III

The question before this court, therefore, is whether strict compliance is required for service of process under section 1608(a), for a foreign state, and under section 1608(b), for an instrumentality of a foreign state. The Magness descendants contend that, even if their attempts at service of process upon the defendants did not strictly comply with section 1608, they substantially complied with the FSIA, and that the defendants had actual notice of the suit. They further argue that, in any event, the Russian Federation waived its right to contest service by appearing at the TRO hearing. The defendants, however, argue that the FSIA makes no provision for anything other than strict compliance with its service of process requirements, and that actual notice cannot substitute for proper service under either section 1608(a) or (b). In addition, the appellants and the United States, as amici, contend that, in any event, the Magness descendants failed to even substantially comply with section 1608(a) or (b). Because service was never effectuated, the district court had no personal jurisdiction over the defendants, they claim, and thus the default judgment should be vacated pursuant to Rule 60(b)(4).

A Section 1608(a)

We conclude that the provisions for service of process upon a foreign state or political subdivision of a foreign state outlined in section 1608(a) can only be satisfied by strict compliance. The express language of the statute requires that service "shall" be made upon a foreign state in the manner prescribed. Moreover, the committee report on the FSIA states that "section 1608(a) sets forth the exclusive procedures for service on a foreign state." H.R. Rep. No. 94-1487, at 24 (1976), U.S. Code Cong. Admin. News at 6604, 6623 (emphasis added). This language simply does not support a finding that anything less than strict compliance will suffice under the law.

This interpretation is in accord with decisions of the Second, Seventh, and D.C. Circuits. In Gray v. Permanent Mission of People's Republic of Congo to United Nations, 443 F.Supp. 816, 821 (S.D.N.Y.), aff'd, 580 F.2d 1044 (2d Cir. 1978), the Second Circuit affirmed a district court holding that, under section 1608(a), "informal notification through channels clearly outside the obvious requirements of the applicable statute cannot be substituted for those which meet the requirements." The court determined that actual notice given the defendant, a foreign state to be served under section 1608(a), was insufficient to meet the requirements of the FSIA. See also Shen v. Japan Airlines, 918 F.Supp. 686, 692 (S.D.N.Y. 1994).

The Seventh Circuit similarly required strict compliance under section 1608(a) in Alberti v. Empresa Nicaraguense De La Carne, 705 F.2d 250, 253 (7th Cir. 1983). In that case, noting that section 1608(a) "delineates the `exclusive procedures' for effecting service of process upon a foreign state," the court refused to excuse the plaintiff's service on the Nicaraguan Ambassador in lieu of the head of the foreign affairs ministry. See also Magnus Elec., Inc., v. Royal Bank of Canada, 620 F.Supp. 387, 389 (N.D.Ill. 1985), aff'd in part, rev'd in part on other grounds, 830 F.2d 1396 (7th Cir. 1987) (holding that "noncompliance with the [FSIA]'s literal requirements (though it certainly did provide notice) deprives this Court of personal jurisdiction.").

The District of Columbia Circuit, holding that "strict adherence to the terms of 1608(a) is required," also rejected the substantial compliance test under section 1608(a) in Transaero, Inc. v. La Fuerza Aerea Boliviana, 30 F.3d 148, 154 (D.C. Cir. 1994), cert. denied, 513 U.S. 1150, 115 S.Ct. 1101, 130 L.Ed.2d 1068 (1995). The court rejected the claim that service upon the Bolivian Ambassador and Consul General in Washington was sufficient under section 1608(a), noting that foreign states, unlike foreign agencies or instrumentalities, may lack the "sophisticated knowledge of the United States legal system" that might otherwise authorize substantial compliance with service provisions. Id.

Based on these decisions, the express language of section 1608(a), and the United States' interest in ensuring that the proper officials of a foreign state are notified when a suit is instituted, we hold that plaintiffs must strictly comply with the statutory service of process provisions when suing a foreign state or political subdivision under section 1608(a).

B Section 1608(b)

The statutory language and case law concerning section 1608(b) present a different question. As such, we are convinced that substantial compliance with the provisions of service upon an agency or instrumentality of a foreign state — that is, service that gives actual notice of the suit and the consequences thereof to the proper individuals within the agency or instrumentality — is sufficient to effectuate service under section 1608(b).

Perhaps most significant to this determination is the express statement in section 1608(b)(3) that delivery under that subsection is authorized "if reasonably calculated to give actual notice." This language reflects the fact that "Congress was there concerned with substance rather than form." Transaero, 30 F.3d at 154. This reference to actual notice is absent from section 1608(a).

Our holding as to section 1608(b) is in accord with the Third, Sixth, Ninth, Eleventh, and D.C. Circuits, all of which have determined that substantial compliance with section 1608(b) is sufficient so long as the defendants have actual notice of the suit. The Third Circuit found that service under section 1608(b) was sufficient absent strict compliance in Velidor v. L/P/G Benghazi, 653 F.2d 812, 821 (3d Cir. 1981). The court noted that "[r]ather than making service on foreign instrumentalities a rigid, technical, or cumbersome procedure, Congress sought to facilitate the ability of private plaintiffs to serve foreign entities." Id. Again, the court concluded that actual notice was the determining consideration. See also Obenchain Corp. v. Corporation Nacionale de Inversiones, 656 F.Supp. 435, 437 (W.D.Pa. 1987), aff'd in part, rev'd in part on other grounds, 898 F.2d 142 (3d Cir. 1990).

The Sixth Circuit adopted a similar substantial compliance test for section 1608(b) in Sherer v. Construcciones Aeronauticas, 987 F.2d 1246 (6th Cir. 1993). The court observed that "the common theme running through [FSIA] cases, whether `substantial compliance' or `strict compliance,' is the importance of actual notice to the defendants." Id. at 1249. The court adopted the substantial compliance approach "under the circumstances in this case," where the defendant had answered the complaint despite the defect in service and had raised twenty-one affirmative defenses. Id. at 1250.

In Straub v. Green, Inc., 38 F.3d 448, 453 (9th Cir. 1994), the Ninth Circuit "formally adopt[ed] a substantial compliance test for the FSIA." The court determined that, under section 1608(b), "the pivotal factor is whether the defendant receives actual notice and was not prejudiced by the lack of compliance." Id. And in Harris Corp. v. National Iranian Radio and Television, 691 F.2d 1344, 1352 (11th Cir. 1982), the Eleventh Circuit similarly adopted the substantial compliance test under § 1608(b), finding that actual notice should override technical deficiencies in service under that section.

Finally, the D.C. Circuit in Transaero, 30 F.3d at 154, noted that "[t]he authorities generally hold that section 1608(b) may be satisfied by technically faulty service that gives adequate notice to the [defendant]." Id. at 153. In authorizing substantial compliance under section 1608(b), the court observed that foreign agencies and instrumentalities, which are "typically international commercial enterprises, often possess a sophisticated knowledge of the United States legal system that other organs of foreign governments may lack." Id. at 154.

C

In sum, virtually no authority suggests that substantial compliance would suffice under section 1608(a) as to foreign governments — the Russian Federation and the Russian Minister of Culture in this case. Nevertheless, the vast majority of the case law does support a holding that substantial compliance under section 1608(b), coupled with actual notice, can suffice to meet the statutory service requirements for instrumentalities of a foreign state. We formally adopt such a test for section 1608(b), but decline to authorize substantial compliance as to section 1608(a).

Having already determined that the Magness descendants failed strictly to comply with either section 1608(a) or (b), we now turn to ascertain whether the plaintiffs substantially complied with the provisions of section 1608(b) as to the Russian State Diamond Fund in this case.

IV

The cases authorizing substantial compliance with the service of process provisions under section 1608(b) note that it is actual notice by the defendant that substantiates the compliance. The Magness descendants assert that the defendants all had actual notice of the suit, while the defendants deny having such notice.

As to the Russian State Diamond Fund, the defendants contend that the mailing of process to Boris Yeltsin and the Russian State Diamond Fund "c/o Deputy Minister of Culture Mikhail Schvidkoy" was not substantial compliance with section 1608(b), which permitted service via a letter rogatory, through the clerk of the court, or as directed by the court. See 28 U.S.C. § 1608(b)(3). The Magness descendants, in turn, assert that they substantially complied with section 1608(b)(3)(B), which authorizes service upon an instrumentality of a foreign state by any form of mail requiring a signed receipt. They point out that they sent service papers to the Texas Secretary of State with a request that those documents be forwarded to the "Russian Ministry of Culture/Russian State Diamond Fund." Finally, the Magness descendants contend that all defendants had actual notice of the suit, as evidenced by the Russian Federation's appearance at the TRO hearing and the confirmation received by the Texas Secretary of State showing that the return receipt for the service documents had been signed by somebody at the "Russian Ministry of Culture/Russian State Diamond Fund."

As the United States notes, there is no evidence that the Magness descendants included a "notice of suit" in the service documents that allegedly were served. The notice of suit is an integral part of the service requirements upon foreign states, and is "designed to provide a foreign state with an introductory explanation of the lawsuit, together with an explanation of the legal significance of the summons, complaint, and service." H.R. Rep. No. 94-1487, at 11, U.S. Code Cong. Admin. News at 6609.

Most importantly, there is no evidence to establish that the defendants had actual notice of the suit. The Magness descendants bear the burden of proving that the defendants had actual notice. See, e.g., Straub, 38 F.3d at 454; Hirsch v. Blue Cross, Blue Shield, 800 F.2d 1474, 1477 (9th Cir. 1986). Under the FSIA, proving "actual notice" requires more than a mere showing that somebody in the foreign state knew of the claim. See Sherer, 987 F.2d at 1250 (finding actual notice only because defendant hired counsel and moved to dismiss the complaint).

Because the plaintiffs have not established that they provided the Russian State Diamond Fund actual notice of the suit, substantial compliance with section 1608(b) was lacking.

V

Having determined that the Magness descendants failed to perfect service under section 1608 as to any of the defendants in this case, we now consider the district court's denial of the defendants' Rule 60(b) motion.

In Seven Elves, 635 F.2d at 402, this court held that a district court should consider eight factors when ruling on a Rule 60(b) motion to vacate a default judgment:

(1) that final judgments should not lightly be disturbed;

(2) that the Rule 60(b) motion is not to be used as a substitute for appeal;

(3) that the rule should be liberally construed in order to achieve substantial justice;

(4) whether the motion was made within a reasonable time;

(5) whether, if the judgment was a default or a dismissal in which there was no consideration of the merits, the interest in deciding cases on the merits outweighs, in the particular case, the interest in the finality of judgments, and there is merit in the movant's claim or defense;

(6) whether, if the judgment was rendered after a trial on the merits, the movant had a fair opportunity to present his claim or defense;

(7) whether there are intervening equities that would make it inequitable to grant relief; and

(8) any other factors relevant to the justice of the judgment under attack.

Analyzing these factors, we must conclude that the default judgment in favor of the Magness descendants should be vacated as to all three defendants. The motion to vacate was made within a reasonable time; the motion is not being utilized as a substitute for appeal; the interest in deciding the merits of the case outweigh the interest in finality; and, the diplomatic implications of this case encourage a consideration of the claim on the merits.

The government has emphasized the weighty diplomatic considerations underlying this case, noting that the United States has fought jurisdiction in instances where foreign attorneys have attempted to serve the United States via non-authorized government employees. In its amici brief the United States suggests that it would not consider itself to have been properly served under the attempts utilized by the Magness descendants in this case. In this light, and for the reasons we have explained, we conclude that the default judgment should be vacated, that the case must be remanded, and that the Magness descendants should be allowed a reasonable time to perfect service upon the defendants.

Therefore, the judgment is VACATED and the case is REMANDED for further proceedings not inconsistent with this opinion.

VACATED and REMANDED.