KELLY, Judge:

Appellant, Kathleen Barndt, appeals from an order of the Court of Common Pleas of Columbia County. The order granted primary physical custody of her sons, Michael and Kristopher, to their father, Joel Barndt, thus modifying a prior decree issued in North Dakota which had granted the appellant primary physical custody. While the appeal raises questions of substantive error, the sole issue addressed in this opinion is whether the courts of Pennsylvania had subject matter jurisdiction to hear the modification petition of the appellee.

Initially, we consider whether subject matter jurisdiction exists under Pennsylvania law. We find that this determination would require remand for factual determinations not made by the trial court. We note that the present record appears to demonstrate an absence of subject matter jurisdiction under Pennsylvania law. We find remand unnecessary, however, as the undisputed facts establish that even if subject matter jurisdiction could be asserted under Pennsylvania law, a federal statute nonetheless bars assertion of such jurisdiction under the facts of the instant case. Consequently, we vacate the orders of the trial court, and relinquish jurisdiction of this case to the courts of North Dakota.

FACTS AND PROCEDURAL HISTORY

The relevant facts may be accurately summarized as follows. Joel and Kathleen Barndt were married in 1977 and divorced in 1983. North Dakota had been the marital domicile. During the course of their marriage, Joel adopted Michael, who was Kathleen's child from a former marriage, and Kristopher was born to the couple. Following the divorce, Kathleen, who had been awarded custody, continued living in North Dakota with the boys. Joel continued to live in North Dakota until December 1985, when he moved into his parents' home in Pennsylvania. In June 1986, the boys came to Pennsylvania for an extended visit which had been arranged and agreed upon by Joel and Kathleen. In March 1987, Joel refused to return the children as agreed and instead petitioned the Columbia County court for custody which was granted by order entered April 10, 1987. The order did not address the jurisdiction of the court.

Subsequent to this change in custody Kathleen appealed to the North Dakota courts to prevent enforcement of the Pennsylvania decree. While not agreeing with this Commonwealth's assumption of jurisdiction, North Dakota declined to take action conflicting with that of the Pennsylvania courts.

Finally, in May 1988, Kathleen Barndt was afforded a hearing in Columbia County to determine the best interests of Michael and Kristopher. Her appeal raised the deficiencies in the conduct of the hearing, quality of the evidence gathered and considered, as well as the deficiencies in the opinion of the trial court issued subsequent to the hearing. These substantive issues can not be reached here, as our review of the record reveals that the courts of Pennsylvania lacked subject matter jurisdiction in the initial proceeding modifying the North Dakota decree, and in all subsequent custody proceedings.

I. AUTHORITY TO RAISE SUBJECT MATTER JURISDICTION SUA SPONTE

In order to have the power to determine the right to custody as between litigants, a court must have subject matter jurisdiction over the person of the child. In re Sagan, 261 Pa. Super. 384, 396 A.2d 450 (1978); Commonwealth ex rel. Graham v. Graham, 367 Pa. 553, 80 A.2d 829 (1951). A court has the inherent power to determine on its own motion whether it has the jurisdiction to decide the cause before it. Douglas v. City of Jeannette, 319 U.S. 157, 63 S.Ct. 877, 87 L.Ed. 1324 (1943); Harris-Walsh, Inc. v. Dickson City Borough, 420 Pa. 259, 216 A.2d 329 (1966). Therefore, even if a party fails to raise this issue by objection or exception in the court below, it is still the affirmative duty of our Court to consider the issue of subject matter jurisdiction. Cathcart v. Crumlish, 410 Pa. 253, 189 A.2d 243 (1963); Marcus v. Diulus, 242 Pa. Super. 151, 363 A.2d 1205 (1976). Orders of a court which is without proper subject matter jurisdiction are without legal force. Commonwealth v. Miller, 306 Pa. Super. 468, 452 A.2d 820 (1982); Commonwealth v. Boerner, 281 Pa. Super. 505, 422 A.2d 583 (1980).

II. APPLICATION OF PA UCCJA

In determining whether the trial court had subject matter jurisdiction we look first to Pennsylvania law. Unfortunately, because the question of jurisdiction was not addressed in the trial court, factual findings essential to a determination of whether subject matter jurisdiction could be asserted over this case under Pennsylvania law, were not made by the trial court. Though the trial court must make these factual determinations initially, we note that the present record contains no facts upon which jurisdiction could be based under Pennsylvania law.

This case involves an interstate custody dispute. The jurisdictional aspects of such disputes are problematic.

Under Article IV, § 1 of the United States Constitution, each state is required to give full faith and credit to the public acts, records and judicial proceedings of every other state. The codification of this constitutional mandate in 28 U.S.C. § 1738, and its precondition that there be finality of judgment, however, left the full faith and credit clause inapplicable to child custody orders. By necessity, such orders are modifiable in the rendering state when the best interest of the child so require; and therefore, such orders lack the necessary finality for protection under the full faith and credit clause. Kovacs v. Brewer, 356 U.S. 604, 78 S.Ct. 963, 2 L.Ed.2d 1008 (1958); New York ex rel Halvey v. Halvey, 330 U.S. 610, 67 S.Ct. 903, 91 L.Ed. 1133 (1947). Additionally, procedural defects may preclude enforcement under the full faith and credit clause of even arguably "final" custody orders. Ford v. Ford, 371 U.S. 187, 83 S.Ct. 273, 9 L.Ed.2d 240 (1962); May v. Anderson, 345 U.S. 528, 73 S.Ct. 840, 97 L.Ed. 1221 (1953). The unfortunate result of this lack of recognition and enforcement of decrees of sister states was the constant uprooting and movement of children from state to state in their parents' efforts to obtain or enforce conflicting custody orders.

In 1977 Pennsylvania became a signatory to the Uniform Child Custody Jurisdiction Act (UCCJA). The purpose of the Act was to provide stability to the home environment and to family relationships by discouraging continuing controversy over child custody and visitation; to avoid jurisdiction disputes; to deter abductions; to avoid relitigation; to promote comity; and to assure that litigation concerning child custody takes place ordinarily in the state in which the child and his family have the closest connection. Commonwealth ex rel. Zaubi v. Zaubi, 275 Pa. Super. 294, 418 A.2d 729 (1980), affirmed 492 Pa. 183, 423 A.2d 333 (1980).

In furtherance of its stated purposes, the UCCJA, as codified in Pennsylvania, (Pa.UCCJA), includes specific provision for situations in which another state has rendered a prior custody order. Under 42 Pa.C.S.A. § 5355, "[i]f a court of another state has made a custody decree, a court of this Commonwealth shall not modify that decree unless: (1) it appears to the court of this Commonwealth that the court which rendered the decree does not now have jurisdiction under jurisdictional prerequisites substantially in accordance with this subchapter or has declined to assume jurisdiction to modify the decree; and (2) the court of this Commonwealth has jurisdiction" (emphasis added).

The intention of the Pa.UCCJA in creating continuing jurisdiction in the initial decree state was to achieve greater stability of custody decrees, and to avoid forum shopping by insuring that the courts of only one state should have responsibility for the custody of a particular child. It was hoped that this would stabilize the home environment of children of divorced parents. In actual practice, as we see in the present case, continuing jurisdiction has often been ignored with jurisdiction assumed inappropriately by a court of a sister state, thus defeating in large measure the intent of the drafters of the uniform act.

The provisions of 42 Pa.C.S.A. § 5344(a) set forth the conditions governing the exercise of jurisdiction over an interstate custody dispute under Pennsylvania law. Because the children had resided in Pennsylvania for the past six months, home state status existed to fulfill the requirement of 42 Pa.C.S.A. § 5344(a)(1)(i). We assume that 42 Pa.C.S.A. § 5344 (a)(3), 5344(a)(4) do not apply. The record reveals that the father's home was satisfactory for placement under 42 Pa.C.S.A. § 5344(a)(5). Hence, the entire question of whether jurisdiction may be asserted properly under Pennsylvania law, turns upon whether the requirement of 42 Pa.C.S.A. § 5344(a)(2) has been met.

Under 42 Pa.C.S.A. § 5344(a)(2), before a Pennsylvania court may assert jurisdiction it must find first that:

(2) it is in the best interest of the child that a court of this Commonwealth assume jurisdiction because:

(i) the child and his parents, or the child and at least one contestant, have a significant connection with this Commonwealth; and

(ii) there is available in this Commonwealth substantial evidence concerning the present or future care, protection, training, and personal relationships of the child.

The Commissioners' notes explaining the applicable section of the model UCCJA in pertinent part provide:

Paragraph (2) perhaps more than any other provision of the Act requires that it be interpreted in the spirit of the legislative purposes expressed in section 1. The paragraph was phrased in general terms in order to be flexible enough to cover many fact situations too diverse to lend themselves to exact description. But its purpose is to limit jurisdiction rather than to proliferate it. The first clause of the paragraph is important: jurisdiction exists only if it is in the child's interest, not merely the interest or convenience of the feuding parties, to determine custody in a particular state. The interest of the child is served when the forum has optimum access to relevant evidence about the child and family. There must be maximum rather than minimum contact with the state.

Uniform Child Custody Jurisdiction Act § 3. (Emphasis added).

Paragraph (2) of the comments refers to what has been adopted as the maximum significant contacts test of 42 Pa.C.S.A. § 5344 (a)(2). Courts of this Commonwealth have followed the rationale of the uniform act's comments in construing the "significant contacts" test as a maximum significant contacts test. Aldridge v. Aldridge, 326 Pa. Super. 49, 473 A.2d 602 (1984) (Kentucky, not Pennsylvania, had proper jurisdiction as that forum would provide the optimum access to relevant evidence on child and family); Commonwealth ex rel Earl R.D. v. Linda H.S., 297 Pa. Super. 78, 443 A.2d 307 (1982) (Vermont had closer connection with child and mother and more substantial evidence was available there than in Pennsylvania). Indeed, Pennsylvania courts have gone so far as to prefer maximum significant contacts over home state status in determining jurisdiction. Bem v. Bem, 316 Pa. Super. 390, 463 A.2d 16 (1983) (significant connections and substantial evidence is sufficient for jurisdiction despite home state jurisdiction elsewhere); Matter of DLS, 278 Pa. Super. 446, 420 A.2d 625 (1980) (separate basis for jurisdiction exists because of Pennsylvania's strong contacts with both parents and children and the availability of evidence); Joseph E.H. v. Jane E.H., 283 Pa. Super. 109, 423 A.2d 739 (1980) (significant contacts existed despite home state status elsewhere).

Application of the maximum significant contacts test to the facts of record in this case would seem to establish a clear absence of jurisdiction under Pennsylvania law. At the time of the petition the boys had only been in Pennsylvania 9 months, and their father had only been here 15 months. It does not appear that their mother had visited Pennsylvania with them for at least 8 years, as Kristopher (age 8 at the time) had never previously been in Pennsylvania, and had never even met his paternal grandparents. (N.T. at 308). Likewise, Michael (age 11) had not seen the paternal grandparents since before his third birthday. (N.T. at 39).

There was no evidence whatsoever concerning Kathleen's custodial qualifications available in Pennsylvania. Joel, though raised in Pennsylvania, left at age 18. (N.T. at 9). He had only returned six months prior to the boys' visit. (N.T. at 7). From the transcript of the hearing, it also appears little could be learned about Joel's custodial qualifications in Pennsylvania at the time he petitioned for custody in March 1987, as he was unemployed most of the time between December 1985 through March 1987, and lived privately with his elderly parents without any apparent ties to the community which would be probative of his custodial qualifications. (N.T. at 38-39).

In view of the extreme paucity of evidence that was available in this Commonwealth in March of 1987 pertaining to the welfare of the children, the comparatively insignificant length of time spent here by the boys and their father, as opposed to the time spent by them in North Dakota, and the continued residence of the custodial parent in North Dakota, we find insufficient evidence upon which an exercise of jurisdiction could be premised by our courts.

However, because the record is arguably undeveloped in this respect, we would be extremely reluctant to vacate the trial court's orders and relinquish jurisdiction to the North Dakota courts on this basis alone. Rather, prudence would seem to dictate a remand for a full inquiry and determination of the factual issues pertinent to the application of the maximum contacts test before rendering such a decision. Federal law, however, renders remand unnecessary.

III. APPLICATION OF FEDERAL LAW

The UCCJA's intent was to create uniformity in the handling of jurisdictional disputes in custody cases. It achieved only limited success, due to the variations in the UCCJA as adopted by each of the states, and the differences in interpretation from court to court within those states. Consequently, there remained wide room for forum shopping, and the flow of children and cases from state to state continued. Federal legislation was finally enacted to bolster the UCCJA, and to enhance uniformity in interpretation and resolution of jurisdictional conflicts involving interstate custody disputes.

In 1980, the United States Congress enacted the Parental Kidnapping Prevention Act (PKPA). The title of the act is misleading and unfortunate, as it was by no means limited to criminal matters relating to kidnapping. Rather, one of the principle purposes of the PKPA was to protect the right of a decree issuing state to exercise exclusive continuing jurisdiction over its child custody orders in certain cases, and to channel custody litigation into the court having continuing jurisdiction by requiring states to give full faith and credit to the custody decrees of states retaining jurisdiction and preventing the issuance of competing decrees. Mark L. v. Jennifer S., 133 Misc.2d 454, 506 N.Y.S.2d 1020 (1986); States ex rel. Valles v. Brown, 97 N.M. 327, 639 P.2d 1181 (1981); Nielsen v. Nielsen, 472 So.2d 133 (La.App. 1985). To this end, the PKPA established national standards to determine jurisdiction in interstate custody disputes. Voninski v. Voninski, 661 S.W.2d 872 (Tn.App. 1982)

Congress' intent to limit the states in the assumption of jurisdiction is evident from the relevant text of the statute:

§ 1738A. Full faith and credit given to child custody determinations

(a) The appropriate authorities of every State shall enforce according to its terms, and shall not modify except as provided in subsection (f) of this section, any child custody determination made consistently with the provisions of this section by a court of another State.

* * * * * *

(c) A child custody determination made by a court of a State is consistent with the provisions of this section only if —

(1) such court has jurisdiction under the law of such State; and

(2) one of the following conditions is met:

(A) such state (i) is the home State of the child on the date of the commencement of the proceeding, or (ii) had been the child's home State within six months before the date of the commencement of the proceeding and the child is absent from such State because of his removal or retention by a contestant or for other reasons, and a contestant continues to live in such State;

(B)(i) it appears that no other State would have jurisdiction under subparagraph (A), and (ii) it is in the best interest of the child that a court of such State assume jurisdiction because (I) the child and his parents, or the child and at least one contestant, have a significant connection which such State other than mere physical presence in such State, and (II) there is available in such State substantial evidence concerning the child's present or future care, protection, training, and personal relationships;

(C) the child is physically present in such State and (i) the child has been abandoned, or (ii) it is necessary in an emergency to protect the child because he has been subjected to or threatened with mistreatment or abuse;

(D)(i) it appears that no other State would have jurisdiction under subparagraph (A), (B), (C), or (E), or another State has declined to exercise jurisdiction on the ground that the State whose jurisdiction is in issue is the more appropriate forum to determine the custody of a child, and (ii) it is in the best interest of the child that such court assume jurisdiction; or

(E) the court has continuing jurisdiction pursuant to subsection (d) of this section.

(d) The jurisdiction of a court of a State which has made a child custody determination consistently with the provisions of this section continues as long as the requirement of subsection (c)(1) of this section continues to be met and such State remains the residence of the child or of any contestant.

(f) A court of a State may modify a determination of the custody of the same child made by a court of another State, if —

(1) it has jurisdiction to make such a child custody determination; and

(2) the court of the other State no longer has jurisdiction, or it has declined to exercise such jurisdiction to modify such determination.

28 U.S.C. § 1738A. (Emphasis added).

First, the statute provides for recognition and enforcement of all decrees made consistent with the provisions of 28 U.S.C. § 1738A. Under 42 Pa.C.S.A. § 5355, the courts of this Commonwealth were permitted to decide whether the decree complied with "jurisdictional prerequisites substantially in accordance with this act." The PKPA has eliminated the opportunity for a state to disregard a foreign decree because of differences in the state's statutory enactment or jurisdictional interpretations of UCCJA provisions. 28 U.S.C. § 1738A(c)(1).

The PKPA also grants a priority to home state jurisdiction in initial custody petitions. Significant connections can only be used as a basis to assume jurisdiction if there is no home state, not as an alternative to the home state. 28 U.S.C. § 1738A(c)(2)(A) and (B).

Finally, and most importantly, the PKPA creates a separate basis for exclusive continuing jurisdiction in the state which issued the original decree. So long as the original decree state continues to have jurisdiction under its own law, and remains the residence of the child or any contestant, it has exclusive continuing jurisdiction over all future custody actions involving that child. 28 U.S.C. § 1738A(c)(2)(E) and (d). That includes the exclusive right to issue modifications or changes in custody. 28 U.S.C. § 1738A(c)(2)(E), (d) and (f); see also Wheeler v. Buck, 452 So.2d 864 (Ala.Civ.App. 1984); Heartfield v. Heartfield, 749 F.2d 1138 (5th Cir. 1985); Kumar v. Santa Clara County Superior Court, 32 Cal.3d 689, 186 Cal.Rptr. 772, 652 P.2d 1003 (1982); Bahr v. Bahr, 442 N.Y.S.2d 687, 108 Misc.2d 920, aff. 458 N.Y.S.2d 247, 91 A.D.2d 1010, appeal denied 454 N.E.2d 1310, 60 N.Y.2d 640, 467 N.Y.S.2d 567 (1983); Flannery v. Stephenson, 416 So.2d 1034 (Ala.Civ.App. 1982); Yacco v. Durley, 457 N.Y.S.2d 384, 117 Misc.2d 69 (1982).

In spite of the basic similarities between the PKPA and the Pa.UCCJA provisions, it is apparent from the differences outlined above that there will be situations in which the application of each will yield a different result. In cases of conflict between the two statutes, it is clear that the PKPA must prevail over any contrary laws of the states in the area of recognition and modification of a sister state's custody decree. See 28 U.S.C. § 1738A; see also In re McBride, 469 So.2d 645 (Ala.Civ.App. 1985); Olivia H. v. John H., 497 N.Y.S.2d 838, 130 Misc.2d 756 (1986); Wheeler v. Buck, supra. Consequently, we cannot make jurisdictional decisions based solely on the Pa.UCCJA, without regard to the PKPA.

Under the PKPA there must be an initial determination of jurisdiction under our own statute, 42 Pa.C.S.A. § 5344. See 28 U.S.C. § 1738A(c)(1). If jurisdiction properly may be assumed under Pennsylvania law, the Pennsylvania court must then look to jurisdiction prerequisites of 28 U.S.C. § 1738A(c)(2)(A) through (E). See Evans v. Evans, 688 F. Supp. 639 (M.D.Tenn. 1987); Serna v. Salazar, 98 N.M. 648, 651 P.2d 1292 (1982). If the court cannot satisfy any one of the PKPA provisions, then the federal statute precludes the Commonwealth's assumption of jurisdiction, and the petition must be denied for lack of subject matter jurisdiction.

However, even if the Commonwealth can satisfy both § 5344 of Title 42, and the PKPA, it may not automatically assume jurisdiction over the dispute. The existing decree of the sister state must be reviewed for compliance at the time of issuance with the provisions of the PKPA outlining the conditions for jurisdiction. Kumar v. Santa Clara County Superior Court, supra; In re Custody of Thorensen, 46 Wn. App. 493, 730 P.2d 1380 (1987); In re McBride, 469 So.2d 645 (Ala.Civ.App. 1985). If the original decree satisfied both PKPA and the laws of the issuing state when entered, then consideration must be given to the possibility that the state which issued the original decree may have exclusive continuing jurisdiction over all custody matters under § 1738A(c)(2)(E) and § 1738A(d) and (f). The decree state must, as of the filing of the petition, no longer have jurisdiction under its own laws, or not satisfy one of the five PKPA jurisdiction conditions in order for this Commonwealth to assert jurisdiction over the dispute.

Should the review of the applicable state law and the PKPA disclose that the decree state still has continuing jurisdiction, the courts of this Commonwealth must refuse to hear the petition and direct the moving party to bring their petition to the courts of the original decree state. Should that state refuse to exercise jurisdiction, then and only then, may the petition be refiled in the courts of this Commonwealth.

In applying the outlined procedure to this case we will assume, arguendo, that Pennsylvania satisfies the first step. Having made this assumption, the propriety of the trial court's exercise of jurisdiction over this dispute turns on the question of whether North Dakota retained exclusive continuing jurisdiction under Section 1738A(d). If at the time of the order North Dakota satisfied its own state law on jurisdiction (which was its version of the UCCJA) and the PKPA, the decree must be honored in this Commonwealth.

There is absolutely no question that North Dakota had proper subject matter jurisdiction to enter the original decree. Both parents and the children had resided in North Dakota for the preceding five years. Consequently, the decree was not subject to modification in Pennsylvania unless North Dakota, at the time the petition for change in custody was filed in March 1987, had lost continuing jurisdiction over the case.

To determine whether or not continuing jurisdiction exists, we again look to North Dakota law to decide whether it would allow for present jurisdiction and whether one of the 28 U.S.C. § 1738A(c)(2) conditions is met. If both are satisfied, only North Dakota has jurisdiction to entertain the petition for change of its custody decree.

North Dakota's jurisdictional alternatives are in keeping with the UCCJA. See North Dakota Cent. Code § 14-14-03. North Dakota case law clearly demonstrates that it would construe North Dakota's UCCJA so as to permit the assertion of continuing jurisdiction under facts such as presented here.

In Dennis v. Dennis, 366 N.W.2d 474 (N.D. 1985), North Dakota issued a custody order in 1981. The children and custodial parent moved to Iowa. Three years later the non-custodial parent, who was still living in North Dakota, petitioned for modification. The North Dakota Supreme Court held that a significant connection with the forum would be sufficient for their continuing jurisdiction under North Dakota law, and to satisfy the continuing jurisdiction of 28 U.S.C. § 1738A(c)(2)(E), which requires only that the state law provide jurisdiction, and the state remain the residence of the child or any party. 28 U.S.C. § 1738A(d). (Emphasis added). Subsequent to Dennis, in Hedstrom v. Berg, 421 N.W.2d 488 (N.D. 1988), North Dakota still used significant connections to satisfy their own jurisdiction as mandated by 28 U.S.C. § 1738A(d) when ruling on a non-custodial parent's right to maintain action in North Dakota after the custodial parent and children relocated.

After reviewing the law in effect at the time of the filing of the March 1987 petition and the current cases, it is apparent that North Dakota would have asserted the authority to exercise jurisdiction over Joel Barndt's petition under North Dakota law. Kathleen has been at all times, since the entry of the original decree through the filing of this appeal, a resident of North Dakota. There is no reason for us to believe that North Dakota, in interpreting their UCCJA, would provide less protection to a resident custodial parent than they have already provided to resident non-custodial parents. Since North Dakota, at the time of the petition, would have had jurisdiction under its own law and under the PKPA, exclusive continuing jurisdiction remained in North Dakota and the Pennsylvania courts did not have subject matter jurisdiction over this case.

CONCLUSION

Based on the foregoing, we find that the trial court should have refused to entertain the petition for custody modification and should have instructed Joel Barndt to direct his petition to the North Dakota courts. As Pennsylvania was without subject matter jurisdiction to modify the North Dakota decree when the trial court entered its orders relating to this custody dispute, the orders are nullities and must be vacated.

The order of April 10, 1987 and all subsequent orders pertaining to the custody of Michael and Kristopher Barndt entered in the Courts of this Commonwealth are hereby VACATED. Physical and legal custody of Michael and Kristopher still lies with Kathleen Barndt pursuant to the North Dakota decree, therefore, Joel Barndt is obligated to return physical custody of the children to Kathleen Barndt in compliance with the North Dakota custody decree without delay. Any modification of the custody arrangements sought by Joel Barndt must be brought in the Courts of North Dakota.

Orders VACATED, Jurisdiction Relinquished to the Courts of North Dakota.

TAMILIA, J., filed a dissenting opinion.

CERCONE, J., filed a concurring opinion.