Under the Family Code of the Philippines, ante-nuptial agreements, also known as marriage settlements, are a vital mechanism for defining property relations between spouses before marriage. These agreements offer flexibility, allowing couples to determine how their property will be managed, owned, and divided. Here is an exhaustive explanation covering all essential aspects:

1. Legal Basis and Nature

Article 74 of the Family Code: The Family Code mandates that future spouses may enter into a marriage settlement to fix their property relations. The Code allows couples to customize their property arrangements through an ante-nuptial agreement, provided it does not contravene law, morals, good customs, public order, or public policy.
Objective: Marriage settlements primarily clarify the economic relationship between spouses, either by opting for the default regime of Absolute Community of Property (ACP) or choosing an alternative arrangement.

2. Key Features of Ante-Nuptial Agreements

Flexibility in Property Regime: Couples may decide on various property regimes other than ACP, such as Conjugal Partnership of Gains (CPG), Complete Separation of Property (CSP), or others as long as they are compliant with legal requirements.
Personalized Provisions: Ante-nuptial agreements can stipulate particular conditions on property ownership, liabilities, income management, and provisions for future children, subject to legal limits.
Freedom of Stipulation: As per Article 1306 of the Civil Code, parties in a contract are free to stipulate anything as long as it is not contrary to law, morals, public policy, or public order.

3. Form and Registration

Written Requirement: The agreement must be in writing, and notarization is required. It ensures that both parties knowingly and voluntarily entered the contract.
Registration with the Local Civil Registry: For enforceability against third parties, the marriage settlement must be registered with the local civil registry where the marriage contract is registered. Without registration, the agreement binds only the spouses and not third parties.
Recording with the Registry of Property: Any agreement involving immovable property should also be recorded in the Registry of Property to ensure that third parties are aware of the arrangement, enhancing its enforceability.

4. Timing of Execution

The ante-nuptial agreement must be executed before the marriage. Property arrangements established after the marriage follow a different set of rules.
Irrevocability upon Marriage: Once the marriage is celebrated, the ante-nuptial agreement generally becomes irrevocable, and the property relations outlined are in full effect. Changes require judicial intervention or mutual consent under specific conditions.

5. Applicable Property Regimes

Absolute Community of Property (ACP):
- Under ACP, all properties owned by the spouses prior to marriage, along with those acquired thereafter, become community property.
- This is the default regime if no marriage settlement is executed.
Conjugal Partnership of Gains (CPG):
- Only properties acquired during the marriage become conjugal; each spouse retains ownership of their properties acquired before marriage.
- The net gains from the joint properties are divided equally upon dissolution of the marriage.
Complete Separation of Property (CSP):
- Spouses agree to retain separate ownership of properties, both acquired before and during the marriage.
- Each spouse retains full control, disposition, and enjoyment of their properties, including any income derived from them.
Other Stipulated Arrangements:
- As long as they do not violate Philippine laws, spouses may define their own unique property relations, including mixed regimes or any other arrangement that suits their needs.

6. Effect of the Ante-Nuptial Agreement on Succession and Family Rights

Inheritance: An ante-nuptial agreement does not typically alter inheritance rights. Spouses and children retain their rights to inherit under the rules of intestate succession, although provisions within the agreement may influence certain rights indirectly.
Family Home: The family home is generally exempt from division and claims under Article 152 of the Family Code. The agreement cannot remove or impair the right of the family to reside in the family home.
Support Obligations: Obligations of mutual support are inherent in marriage and are not waivable by an ante-nuptial agreement.

7. Limits and Prohibitions

Contrary to Law, Morals, and Public Policy: Agreements that attempt to waive certain statutory rights or obligations, such as support, are void.
Limiting Inheritance Rights: Any provision that unfairly deprives a spouse or child of their legitime (reserved inheritance share) is void.
Prospective Waiver of Marital Rights: Provisions waiving future rights to support or attempting to predetermine custody and support of future children are generally unenforceable.

8. Modifications Post-Marriage

Mutual Consent with Judicial Approval: Post-marriage changes to the property relations require mutual consent, judicial approval, and typically occur only under serious justifying reasons, such as insolvency or incapacity.
Court Supervision for Minor Changes: For instance, any agreed changes involving the family home or essential marital rights might require court supervision to ensure fairness and public policy adherence.

9. Effect on Third Parties

Binding Nature with Registration: If properly registered, third parties are bound by the terms of the agreement. This protects creditors and others who deal with the spouses, ensuring transparency regarding the property relations.
Liabilities and Credits: The regime chosen influences liabilities and how creditors may claim. For example, under CSP, only the spouse incurring the debt is responsible for it, whereas, under ACP, both spouses may be jointly liable.

10. Dissolution of the Marriage and the Ante-Nuptial Agreement

Dissolution by Death or Annulment: Upon death, annulment, or legal separation, the ante-nuptial agreement’s terms determine the division of assets. Under ACP or CPG, property is divided equally, while in CSP, each retains their individual assets.
Effect of Nullity or Void Marriages: If the marriage is declared void ab initio, the property relations revert to co-ownership, unless one or both spouses acted in bad faith.

11. Recognition and Enforcement of Foreign Ante-Nuptial Agreements

Recognition of Foreign Settlements: If the couple enters into an ante-nuptial agreement abroad, the agreement may be recognized in the Philippines, provided it complies with Philippine law.
Conflict of Laws: When foreign law is involved, the principle of lex loci celebrationis (law of the place of marriage) applies to the marriage's validity, but property relations must comply with Philippine law if the spouses reside or hold property in the Philippines.

12. Implications of Non-Existence of a Marriage Settlement

Default to ACP: If the spouses do not execute a marriage settlement before the marriage, the property relations default to Absolute Community of Property.
Application of Family Code Provisions: All legal rules on ACP apply, including co-ownership, joint management, and shared debts and liabilities.

These provisions underscore the importance of careful planning and proper legal guidance when crafting ante-nuptial agreements. They protect individual and shared interests, allowing spouses to enter into a clear, mutually agreed-upon financial arrangement that respects their autonomy and marital rights.