This is to update the sticky in this thread area.
First, Missouri does NOT have any set procedure/process/statute by which a minor may become emancipated. As such, the courts do not have an "forms" for a minor (or lawyer) to use or copy. Under Rule 87.01 of the Missouri Rules of Civil Procedure, however, a person (including a minor) may obtain DECLARATORY RELIEF "in any instance in which it will terminate a controversy or remove an uncertainty" and, additionally, to obtain a declaration of rights, status, or legal relations.
WHERE to file the petition is not entirely clear, but often the petition is filed in the county where the petitioning minor is then residing. Notably, any objection to the Court's venue must be asserted as an affirmative defense and, if not timely raised, any objection to venue is considered waived.
Second, any minor who wants to file a Petition for a Declaration Judgment to have himself/herself declared an "emancipated minor" must FIRST petition the Court for the appointment of a "next friend" to actually FILE the Petition for a Declaratory Judgment. If the minor is under the age of 14 years old, the petition for appointment of "next friend" must be made by an adult. If the minor is at least 14 years old, then the MINOR can actually file and submit the petition for appointment of the "next friend" (and, once granted, the next friend files the Petition for Declaratory Judgment).
Third, under Missouri common law, emancipation can occur by (1) express consent of the minor's parents; (2) by implied parental consent; or (3) by the minor's change of status in the eyes of society. Notably, "self sufficiency" is not a listed element for obtaining "emancipation" under Missouri common law.
On its face Mo. Rev. Stat. Section 452.340.3 applies only when a parent is seeking to end "child support" for an "emancipated minor," but, logically, a Missouri court may utilize the statutory factors listed when presented with a Petition filed by a minor seeking "emancipation" from his or her parents. Under the statute, "child support" can be ended - and, thus, emancipation can be granted - when a minor child becomes self-supporting, provided the custodial parent has relinquished the child from parental control by express of implied consent."
There is not much case law on the matter, but what case law there is provides that the statutory phrase "self-supporting" does NOT mean that a child must be totally self-sufficient and decline all forms of financial assistance. Even when the petitioning minor receives "significant financial assistance and other material support from others, including the custodial parent" will NOT necessarily defeat a claim that the minor child is "emancipated." Sparks v. Trantham, 814 S.W.2d 621 (Mo. App. S.D. 1991). Thus, under Missouri law, a minor need not be totally financially independent in order to be emancipated.
As a practical matter, the Court will want to give notice to the parents that the petition has been filed by the minor child OR, alternatively, it will wise to have both parents (if both alive and consenting) attend any hearing on the petition.
Obviously, it is easier to convince a Missouri Court to grant a Petition for Declaration of Emancipation if both parents (if both living) give their express consent. Usually, "express consent" can take the form of a signed, notarized statement from each parent. The court may also want testimony at the hearing to insure that the parent hasn't changed his/her mind since signing the affidavit.
In some cases, you might be able to obtain a parent's express consent by pointing out to the parent that an "emancipated minor" can receive more financial aid for college because the parents' financial information will not be considered or taken into account for financial aid purposes. See, the Free Application for Federal Student Aid (FAFSA). (note: the MERE ending of child support under Statute 452.340 does NOT equal "emancipated minor" for purposes of federal financial aid purposes; a minor MUST have a judgment declaring the emancipation of the minor child to be effective for financial aid purposes). Other factors that may be considered by the Court include: (1) whether the petitioning minor lives outside of the parental home (e.g., with a friend, grandparents, etc.); whether the petitioning minor earns and is solely responsible for his/her own money (has a job, controls the banking, etc.); whether the petitioning minor has the maturity to be emancipated (no criminal conduct, doing well in school, etc.); and the reasons why the petitioning minor wants to be emancipated (one or both parents are alcoholics and its a toxic environment, etc.). It may be easier to get the Court to grant a declaratory judgment petition for emancipation during the year in which the petitioning minor is 17 y.o. because the minor child will, effectively, be able to be "emancipated" when they turn 18 y.o. anyway.
Emancipation by "implied consent" will requiring a hearing in which competent evidence of the "implied consent" will have to be provided. If the parents fail to show at the hearing after being given proper notice thereof, that can be argued as implied consent (in addition to any other evidence of "implied consent").