Mother appeal's from a judgment granting the Quinns’ petition to adopt her child after the trial court denied her motion to dismiss the petition for adoption. ORS 109.350. The Quinns cross-assign as error the admission in evidence of an affidavit of the Registrar of the Cherokee Nation of Oklahoma. On de novo review, ORS 19.125(3), we reverse.
On the day her son was born, mother signed documents to voluntarily relinquish him for adoption to the Quinns. The documents included a consent to adoption, which became irrevocable under state law after certain requirements were met. ORS 109.312(2)(a). Before the adoption judgment was entered, mother filed a revocation of consent to adoption and moved to dismiss the adoption petition. Her revocation was based, in part, on the Indian Child Welfare Act (ICWA), 25 USC §§ 1901 et seq. She claims that child is an Indian child, as defined in ICWA, and that she is, therefore, entitled to revoke her consent to adoption. See 25 USC § 1913(c).
According to mother’s evidence, she became a member of the Cherokee Nation of Oklahoma a week before the hearing on her motion to dismiss the adoption proceeding, and child was then eligible for membership in the tribe.1 If that evidence is true, child is an “Indian child,” as defined in ICWA:
“ ‘Indian child’ means any unmarried person who is under age eighteen and is either (a) a member of an Indian tribe or (b) is ehgible for membership in an Indian tribe and is the biological child of a member of an Indian tribe[.]” 25 USC § 1903(4).
The trial court denied mother’s motion to dismiss the adoption petition. It held that ICWA does not apply, because mother was not a member of an Indian tribe when the consent became irrevocable under state law. Mother assigns that ruling as error.
*582The trial court erred. If child met the definition of an Indian child at the time of the hearing, mother is entitled to revoke her consent to adoption. 25 USC § 1913(c) provides:
“In any voluntary proceeding for termination of parental rights to, or adoptive placement of, an Indian child, the consent of the parent may be withdrawn for any reason at any time prior to the entry of a final decree of termination or adoption, as the case may be, and the child shall be returned to the parent.” (Emphasis supplied.)
The plain meaning of that statute is that the consenting parent has until entry of the final adoption or termination judgment to revoke consent to adoption. State adoption law cannot interfere with that federal right. So long as a final decree of adoption or termination has not been entered, the parent can revoke. There is no requirement that membership or eligibility for membership in the tribe must be established before the consent is signed or becomes irrevocable under state law, when consent can become irrevocable without court action.
In reaching its contrary conclusion, the trial court relied on Matter of Adoption of Infant Boy Crews, 60 Wash App 202, 803 P2d 24 (1991), which held that ICWA does not apply to a voluntary adoption, because the mother was not a member of a tribe at the time her parental rights were voluntarily terminated by court order. Under Washington law, the court enters an order approving the petition for relinquishment of the child. That order terminates the relinquishing parent’s parental rights. RCW 26.33.090. In Crews, neither the mother nor the child was a member of an Indian tribe when the mother relinquished the child. The trial court entered a final order approving relinquishment and terminating parental rights. Later, but before the adoption was final, the mother established her membership in an Indian tribe and the child’s eligibility for membership. The Court of Appeals rejected the mother’s attempt to revoke, because the final termination order had been entered before the child became an Indian child as defined by ICWA.
In contrast, here, according to mother’s evidence, child became an Indian child before the court had entered a final judgment of termination or adoption. That fact alone distinguishes this case from Crews. If mother establishes *583that, before the “entry of a final decree of termination or adoption,” 25 USC § 1913(c), child was an Indian child as defined in ICWA, she is entitled to revoke her consent to adoption for any reason up until the time the adoption judgment is entered. There is nothing in ICWA that requires that tribal affiliation be established before the consent is signed or becomes irrevocable under state law.
The dissent would adopt the reasoning used by the Washington Supreme Court in its decision affirming the Court of Appeals in Crews, 118 Wash 2d 561, 825 P2d 305 (1992), to conclude that ICWA should not apply in this case. That court said that ICWA was not intended to apply
“when an Indian child is not being removed from an Indian cultural setting, the natural parents have no substantive ties to a specific tribe, and neither the parents nor their families have resided or plan to reside within a tribal reservation. In such a situation, whether or when a child meets the definition of ‘Indian child’ under ICWA is not controlling.” 118 Wash 2d at 571.
It is worth noting that the Quinns do not rely on that reasoning here; their argument is purely related to the timing of the tribal membership. In any event, the analysis is clearly wrong. It adds, as a matter of state law, a requirement to ICWA that Congress did not impose: i.e., that a child who meets the ICWA definition of “Indian child” is nonetheless not protected by ICWA, unless the child is being removed from an existing Indian cultural setting. 117 Or App at 591.
That is directly in conflict with the idea of tribal sovereignty and the policy of improving tribal ties reflected in ICWA. It also involves exactly the type of state court interference that ICWA was intended to protect against. If ICWA does not apply because the parent is not “Indian” enough for a particular state court, the protection afforded to the child, the parents and the tribe is defeated. As the Supreme Court said:
“It is clear from the very text of the ICWA, not to mention its legislative history and the hearings that led to its enactment, that Congress was concerned with the rights of Indian families and Indian communities vis-a-vis state authorities. * * * Congress perceived the States and their courts as partly *584responsible for the problem it intended to correct.” Mississippi Band of Choctaw Indians v. Holyfield, 490 US 30, 44, 109 S Ct 1597, 104 L Ed 2d 29 (1989). (Footnote omitted; emphasis supplied.)
Congress has made the policy decision about the strength of the connection that a parent and child must have with the tribe for ICWA to apply — that the child be a member of the tribe or that the child be eligible for membership and the biological child of a member. 25 USC § 1903(4). It is not for state courts to add additional requirements, as the dissent would do.2
*585The Quinns cross-assign error to the court’s admission, over their hearsay objection, of the affidavit of the Registrar of the Cherokee Nation of Oklahoma to show that mother is a member of the tribe and that the child is eligible for membership. Mother makes no argument for the admissibility of the affidavit other than to say that it was properly admitted as part of a stipulation. It was not part of a stipulation.3 We agree with the Quinns that the affidavit is hearsay and, in the absence of any contention that its admission falls within an exception to the hearsay rule, the trial court erred when it admitted it. See OEC 802.
The Quinns argue that, without the affidavit, mother did not prove that ICWA applied and, therefore, mother could not revoke her consent. They urge us to affirm the adoption judgment on that basis. Because the trial court overruled the hearsay objection and admitted the affidavit, mother never had any reason to offer other evidence on the same issue. The Quinns never challenged the sufficiency of the evidence regarding child’s Indian status.4 To say now that, because the *586evidence that she offered was inadmissible, she has not established one of the elements of her claim, would not only be an improper use of appellate procedure,* ***5 it would also be grossly unfair.
We cannot know whether, had the trial court made the correct ruling on the evidence issue, mother could have presented other, admissible, evidence to prove child’s connection with the tribe. Particularly in the light of the fact that there is nothing in the record to indicate that there was a genuine dispute about mother’s or child’s Indian status or about the accuracy of the information included in the affidavit, we will not use the trial court’s error to deny mother the opportunity to meet the objection with admissible evidence.
The dissent laments the injustice of undoing the relationship and bonding that has occurred while this case has made its way through the courts. Under that analysis, however, we could never correct an erroneous custody determination, because of its adverse effects on the child and the adoptive parents.
We must remember that mother did not cause the delay in this case. When she sought to revoke her consent in April, 1991, child was 13 days old. Mother was entitled to regain custody at the latest by the time of the hearing, when child was 31/2 months old. The Supreme Court, faced with an even longer passage of time, said:
“We are not unaware that over three years have passed since the twin babies were born and placed in the [adoptive] home * * *. Three years’ development of family ties cannot be undone, and a separation at this point would doubtless cause considerable pain.
*587“Had the mandate of the ICWA been followed in 1986, of course, much potential anguish might have been avoided, and in any case the law cannot be applied so as automatically to ‘reward those who obtain custody, whether lawfully or otherwise, and maintain it during any ensuing (and protracted) litigation.’ ” Mississippi Band of Choctaw Indians v. Holyfield, supra, 490 US at 53 (quoting In re Adoption of Halloway, 732 P2d 962, 969 (Utah 1986)). (Emphasis supplied.)
As unpleasant as it is to apply the law as Congress has written it, we are required to do that.
Mother is entitled to reversal. The case shall be remanded for rehearing, excluding the hearsay evidence.6
Reversed and remanded for proceedings not inconsistent with this opinion.
The affidavit of the registrar of the tribe states that mother “is a duly registered member of the Cherokee Nation of Oklahoma” and that “any biological child of [mother] is eligible for membership in the Cherokee Nation of Oklahoma.” Although the affidavit does not say when mother’s membership was effective, mother does not assert that she was a member any earlier than the week before the hearing.
The dissent’s reliance on Mississippi Band of Choctaw Indians v. Holyfield, supra, for the proposition that “[o]ther courts have held that the ICWA does not apply when children are not being removed from existing Indian cultural settings,” 117 Or App at 591, is, at best, curious. In Holyfield, the Court held that the tribal court had exclusive jurisdiction over the adoption of two Indian children, despite the fact that the parents had purposefully arranged for their births off the reservation and for their adoption by the Holyfields. 490 US at 40. The Court recognized that one of the purposes of ICWA is to promote “stability and security of Indian tribes.” 490 US at 49 (quoting 25 USC § 1902). It said:
“[Exclusive tjribal jurisdiction under § 1911(a) was not meant to be defeated by the actions of individual members of the tribe, for Congress was concerned not solely about the interests of Indian children and families, but also about the impact on the tribes themselves of the large numbers of Indian children adopted by non-Indians. * * * The numerous prerogatives accorded the tribes through the ICWA’s substantive provisions [including presumptive jurisdiction over non-domiciliaries] must, accordingly, be seen as a means of protecting not only the interests of individual Indian children and families, but also of the tribes themselves.” 490 US at 49. (Citations omitted.)
The consequences of holding that ICWA is not applicable are not only that the parent may not revoke consent to adoption; it also deprives the tribal court of presumptive jurisdiction and its right to intervene in state court proceedings involving the Indian child. See 25 USC § 1911(b), (c). That deprivation defeats the purpose of ICWA to “ ‘protect the rights of the Indian child as an Indian and the rights of the Indian communiiy and tribe in retaining its children in its society.’ ” Mississippi Band of Choctaw Indians v. Holyfield, supra, 490 US at 37 (quoting H R Rep No. 95-1386 at 23 (1978)). If the tribe has a right to intervene, or to assert jurisdiction of its own court, it may well decide that a child who meets the definition of Indian child, although bom of parents who are notin an “existing Indian cultural setting,” should be returned to the tribe rather than being placed in a non-Indian adoptive home. That is the tribe’s, not the state court’s, decision. Engrafting a new requirement into ICWA that allows the dominant society to judge whether the parent’s cultural background meets its view of what “Indian culture” should be puts the state courts right back into the position from which Congress has removed them. That would be especially ironic, in that one of the reasons that the parents may not be involved in their Indian culture could be the very policies of removal of Indian children that ICWA was intended to counteract. See Mississippi Band of Choctaw Indians v. Holyfield, supra, 490 US at 50 n 25. If state courts impose their own value system on these decisions, the tribes will never be able to regain members who have been lost because of earlier government policies.
The purported stipulation on which mother relies occurred during a colloquy between the court and counsel:
“THE COURT: Make an opening statement if you wish. Leave out the adjectives, you know what I mean.
“[MOTHER’S COUNSEL]: Before I start, I believe [counsel] and I have a stipulation that the Cherokee Nation of Oklahoma is a group of Indians that is recognized to [sic] services provided Indians by the Secretary of the Interior, of the United States.
“THE COURT: You have stipulated, that’s all that is necessary.
“[MOTHER’S COUNSEL]: And that [mother] became a registered member of the Cherokee Indian Nation —
“THE COURT: As of last week, July 19,’91.
“[MOTHER’S COUNSEL]: Correct, and I have a document that came yesterday from the Cherokee Nation to establish that. It’s our position that since the adoption has not been granted yet, under Federal Law, she is entitled to withdraw her consent to adoption anytime before the final decree is entered.”
The Quinns argue that they did not stipulate to mother’s tribal membership. Even if the stipulation was as mother contends, it does not include the affidavit, nor does it establish that child is either a tribal member or eligible for membership.
The dissent accuses us of ignoring the Quinns’ memorandum, in which they asserted that neither child nor mother is a member of the tribe. The memorandum was filed on the day of the hearing; there is no indication that it was responsive to the evidence presented at the hearing. Further, the objection that was made to the affidavit was a general hearsay objection. There was no argument regarding the basis for the Quinns’ concern, for example, that the affidavit is not reliable. The Quinns have never asserted, either in the trial court or in this court, that there is anything *586about the affidavit that is unreliable. Indeed, it is unlikely that they would assert the unreliability of an affidavit made by the same person on whose hearsay letter they relied in their memorandum as proof that child is not an Indian child. We do not know what their concern about the affidavit is, and their failure to argue that at the hearing deprived mother of the opportunity to meet the concern.
Although we can affirm despite an evidentiary error, because evidential error is not presumed to be prejudicial, OEC 103(1), we know of no authority for affirming because of a prejudicial evidentiary error. When evidence material to the case has been incorrectly admitted, the appropriate disposition is remand for rehearing, excluding the inadmissible evidence.
On remand, the trial court is directed to ICWA guidelines promulgated by the Bureau of Indian Affairs. 44 Fed Reg 67,584 (1979). Although the guidelines are not binding on the courts, they are instructive. Under the heading “Pretrial requirements,” the guidelines provide:
“B.l. Determination That Child Is an Indian
“(a) When a state court has reason to believe a child involved in a child custody proceeding is an Indian, the court shall seek verification of the child’s status from either the Bureau of Indian Affairs or the child’s tribe. In a voluntary placement proceeding where a consenting parent evidences a desire for anonymity, the court shall make its inquiry in a manner that will not cause the parent’s identity to become publicly known.” 44 Fed Reg at 67,586. (Emphasis supplied.)
There can be no doubt that the trial court in this case has “reason to believe’ ’ that an Indian child is involved; indeed, it accepted, albeit erroneously, mother’s evidence establishing that fact. To further the purposes of ICWA, the trial court should not enter a judgment of adoption until it verifies whether or not child is an Indian child.