Below is a comprehensive legal discussion on the validity of tribal marriages in the Philippines—and what happens when spouses who married under tribal customs separate after a long period, such as seventeen (17) years. The information provided is based on statutes, administrative regulations, and jurisprudence applicable as of this writing.

1. Overview of Tribal Marriages in the Philippine Legal System

In the Philippines, the general legal framework for marriage is primarily governed by the Family Code of the Philippines (Executive Order No. 209, as amended). However, not all marriages fall strictly under the Family Code. Specific groups—particularly Indigenous Cultural Communities/Indigenous Peoples (ICCs/IPs)—can validly marry under their own customary laws and traditions, pursuant to the Indigenous Peoples’ Rights Act of 1997 (“IPRA,” Republic Act No. 8371) and the 1987 Philippine Constitution’s recognition of cultural diversity.

1.1 Recognition under the 1987 Constitution

Cultural integrity: The Constitution mandates the State to recognize, respect, and protect the rights of ICCs/IPs to preserve and develop their cultures, traditions, and institutions.
Pluralistic legal framework: This policy environment acknowledges that some communities still observe customary marriage rites that differ from the mainstream processes under the Family Code.

1.2 Indigenous Peoples’ Rights Act (R.A. No. 8371)

Customary laws: The IPRA expressly provides that the State shall recognize, respect, and protect the rights of ICCs/IPs to preserve their customs, traditions, and institutions.
Marriage practices: IPRA affirms that marriages solemnized in accordance with indigenous customary laws have legal effect if they are not contrary to the Constitution, national policies, and public morals.

Thus, tribal marriages—performed in compliance with indigenous customary laws—are recognized as valid in the Philippines, subject to compliance with certain legal formalities for registration and public policy considerations.

2. Legal Requirements and Formalities

2.1 Who Can Solemnize Tribal Marriages?

Under customary law, a tribal leader, elder, or shaman (depending on the specific ethnic community) may solemnize the marriage. This is often recognized as a valid act by virtue of tradition and custom. Unlike in mainstream civil or church marriages, there may be no uniform set of documentary requirements, but it typically includes:

Consent of the parties (and often the extended families or clan elders).
Ceremonial rites prescribed by the particular tribal tradition.
Witnesses from the community, typically clan elders or recognized leaders.

2.2 Registration with the Civil Registry

Certificate of Marriage: After the wedding rituals, some IP communities execute a marriage certificate in the form prescribed by local custom, or a special “Tribal Marriage Certificate” recognized by the Philippine Statistics Authority (PSA).
Civil Registry Filing: The local civil registry where the ceremony took place may record the marriage upon presentation of an appropriate affidavit or proof from a recognized tribal leader.
Importance of Registration: While registration is not strictly required for the marriage to be valid between the parties, it is crucial when dealing with property relations, inheritance, spousal benefits, or future litigation. Registration secures official recognition by the government, which is beneficial to both spouses for legal clarity.

2.3 Public Policy Limitations

Even though the State recognizes customary laws, the following limitations typically apply:

Minimum age requirements: Marriage under tribal custom cannot legalize unions below the allowable marrying ages under national law (presently 18 years old).
No violence or coercion: Forced marriages or those involving violence are not recognized.
No polygamous arrangements, unless one is referring to Muslim marriage under the Code of Muslim Personal Laws (P.D. 1083). For non-Muslim indigenous communities, polygamy is typically not recognized by mainstream courts if it contradicts national policies.
Prohibitions against incest: Customary law cannot validate marriages within prohibited degrees of consanguinity or affinity, consistent with the Family Code’s public policy.

3. Legal Effects of a Tribal Marriage

Once deemed valid, a tribal marriage produces the same legal consequences as any civil or church marriage recognized under Philippine law, including:

Duties of fidelity, mutual support, cohabitation, and respect under the Family Code.
Property regime: Depending on when it was contracted and if the spouses did not opt for a specific property regime, the Absolute Community of Property (for marriages after the effectivity of the Family Code in 1988) or Conjugal Partnership of Gains (for older marriages) may apply.
Succession rights: Each spouse is considered an heir to the other, and children born within the marriage are legitimate, with inheritance rights protected by law.
Spousal benefits: Rights such as health insurance, social security benefits, and other entitlements accorded to married persons.

4. Dissolution or Separation After Many Years (e.g., After 17 Years)

4.1 No Absolute Divorce for Non-Muslim Indigenous Groups

Under Philippine law, absolute divorce is not permitted for non-Muslim Filipinos. This rule applies as well to tribal marriages unless the tribe’s customary laws provide for a form of divorce or dissolution recognized under IPRA and not in conflict with national policy. However, the Supreme Court often requires a judicial confirmation of such a customary dissolution before it is given force nationwide—especially when one party tries to remarry.

4.2 Grounds for Annulment, Nullity, or Legal Separation Under the Family Code

If the tribal marriage is recognized as valid, then any legal dissolution may be pursued under the Family Code’s provisions on:

Declaration of Nullity of Marriage: If the marriage is void from the start (e.g., bigamous, incestuous, lack of a valid solemnizing officer recognized by custom, or one party was underage without parental consent).
Annulment: If the marriage is valid but voidable under specific grounds (e.g., lack of parental consent if between 18 and 21 years old at the time, psychological incapacity, fraud, force, or intimidation, etc.).
Legal Separation: If a spouse seeks separation of bed and board but not the total dissolution of the marriage bond, for reasons such as repeated physical violence, drug addiction, infidelity, or abandonment.

It should be noted that the standards for annulment or nullity under the Family Code apply uniformly, whether it is a mainstream or tribal marriage, once that tribal marriage is recognized by law.

4.3 Customary Dissolution of Marriages in Certain Tribes

Some indigenous groups observe customary procedures that allow spouses to separate and treat the marriage as ended within their community. While such dissolution may be accepted within the tribe, challenges may arise when dealing with:

Property in mainstream contexts (e.g., land titled under the Torrens system).
Subsequent remarriage in civil or church contexts.
Inheritance disputes if a spouse passes away.

If the dissolution was entirely through tribal custom, it may or may not be recognized legally unless a court (or a duly authorized agency) declares the marriage dissolved in accordance with national law or recognizes such tribal dissolution under IPRA. Parties are advised to register or confirm the dissolution in the civil registry if possible.

5. Legal Concerns After a Long Separation (17 Years)

Presumption of Marriage Validity: If the tribal marriage was validly entered into, it remains valid until legally annulled, declared void, or dissolved by recognized customary processes that are then accepted by the State.
Property Issues: If no formal legal separation, annulment, or dissolution took place, the spouses are generally presumed to remain under the same property regime. Any property acquired during the marriage could be considered part of the community or conjugal partnership.
Child Legitimacy: Any children born during the marital union or shortly thereafter are deemed legitimate unless rebutted. This affects claims for support, inheritance, or legitimacy.
Spousal Support: Absent a legal separation decree or final dissolution, each spouse may still claim support from the other based on need and capacity to give support.
Remarriage: If a spouse remarries without a legal or recognized dissolution, the second marriage may be considered bigamous under the Revised Penal Code.

6. Practical Considerations and Recommendations

Document the Marriage: If you are part of an indigenous community and have married under tribal rites, ensure you obtain and register a “Tribal Marriage Certificate” or equivalent document through the local civil registry and the Philippine Statistics Authority (PSA). This prevents future doubts about the existence and validity of the marriage.
Check Customary Law: If you seek dissolution of a tribal marriage, carefully inquire whether your tribe has established customs allowing for divorce or separation. Secure written proof or a certification from tribal authorities, but remain mindful that you may still need judicial confirmation for full effect under national law.
Seek Legal Counsel: If separation or dissolution is contemplated, consult a legal professional. Complex issues can arise related to property rights, inheritance, parental authority over children, and potential criminal liability for bigamy should one remarry without a recognized dissolution.
Court Declaration: Where tribal custom provides for separation, consider obtaining a court declaration to ensure full effect outside of the indigenous community—especially important for property transactions, future remarriage, or dealings with government agencies.

7. Conclusion

Tribal marriages hold a recognized and valid place within Philippine family law, thanks to constitutional and statutory safeguards for indigenous customs and traditions. As long as they meet minimum legal criteria and do not violate fundamental public policy, marriages solemnized under indigenous customary laws are valid nationwide. However, prolonged separation—such as a 17-year separation—does not by itself terminate the marriage in the eyes of the law.

Dissolution of a tribal marriage, just like a mainstream civil or church marriage, requires either:

Compliance with tribal customary divorce processes recognized under IPRA and confirmation by the courts or relevant agencies, or
Resort to the Family Code’s remedies (annulment, declaration of nullity, or legal separation).

Without such legal or recognized customary dissolution, spouses remain legally married, and property and family-related rights remain intact. Given the complexities that often arise (property distribution, inheritance, remarriage, child legitimacy, etc.), individuals in tribal marriages who plan to separate or remarry should seek competent legal assistance to protect their rights and avoid future disputes.