The intersection of Philippine family law and international paternity creates a complex legal landscape for children born to U.S. citizens in the Philippines. Whether the parents were married, in a common-law relationship, or had a transient encounter, the Philippine legal system prioritizes the "best interests of the child" and the mandatory obligation of parents to provide support.

I. The Legal Basis for Support

Under the Family Code of the Philippines, support (sustento) is a comprehensive obligation. It is not merely a cash payment but encompasses everything indispensable for sustenance, dwelling, clothing, medical attendance, education, and transportation.

Compulsory Nature: Support is a matter of public policy. It cannot be waived, renounced, or settled for future claims.
Reciprocity: The obligation to support is mutual between parents and children, but in the context of minors, the burden falls heavily on the parents.

II. Determining Paternity: The Prerequisite

Before a U.S. citizen can be legally compelled to pay support in a Philippine court, paternity must be established.

Legitimate Children: If the child was born during a valid marriage between the U.S. citizen and the Filipino mother, paternity is legally presumed. Support can be demanded immediately.
Illegitimate Children: If the parents were not married, the child must be "recognized." This happens through:

The Record of Birth signed by the father.
An Affidavit of Admission of Paternity.
A private handwritten instrument where the father admits paternity.

Compulsory Recognition: If the father refuses to acknowledge the child, the mother must file an action for "Compulsory Recognition" (Paternity Suit). Philippine courts allow DNA testing as evidence to establish the biological link.

III. Calculating the Amount of Support

Unlike many U.S. states that use rigid "Child Support Calculators" based on fixed percentages, the Philippines follows the Principle of Proportionality (Article 201, Family Code).

The amount is never fixed and is determined by two moving variables:

The Necessities of the Child: The child’s standard of living should, as much as possible, reflect the social standing of the family.
The Resources/Means of the Giver: The court looks at the U.S. citizen's income, properties, and overall financial capacity.

Note: Because the cost of living is lower in the Philippines, a U.S. salary often results in a support order that is substantial by local standards but may be lower than a comparable U.S. court order.

IV. Extraterritorial Enforcement

Enforcing a Philippine support order against a U.S. citizen residing in the United States involves international legal cooperation.

The Hague Convention: Both the United States and the Philippines are signatories to the Hague Convention on the International Recovery of Child Support and Other Forms of Family Maintenance. This allows for the recognition and enforcement of support orders across borders.
U.S. State Authorities: Through the Convention, a Philippine support order can be sent to the U.S. Department of Health and Human Services (HHS) and subsequently to state Child Support Enforcement (CSE) agencies to initiate wage garnishment or asset seizure in the U.S.

V. Criminal Liability for Non-Support

The Philippines has stringent laws regarding the economic abuse of women and children.

Republic Act No. 9262 (VAWC): The denial of financial support can be classified as Economic Abuse. U.S. citizens residing in or visiting the Philippines can be criminally charged under this act.
Hold Departure Orders (HDO): If a criminal case is filed under R.A. 9262, the court can issue an HDO, preventing the U.S. citizen from leaving the Philippines until the support issue is resolved or bail is posted.

VI. The "Immigration" Connection

While child support is a civil/criminal matter, it can impact a U.S. citizen’s standing:

Consular Reports of Birth Abroad (CRBA): To transmit U.S. citizenship to the child, the U.S. father must generally agree in writing to provide financial support until the child reaches 18 (under 8 U.S.C. § 1409).
Passport Revocation: Under U.S. federal law (the PRWORA), if a U.S. citizen owes more than $2,500 in back child support, their U.S. passport may be revoked or denied renewal by the Department of State.

Summary Table: Support Factors

Factor	Description
Age of Child	Support is mandatory until age 18, but extends if the child is still in school.
Education	Includes schooling, even beyond age 18, until the child finishes a trade or profession.
Adjustment	Support can be increased or decreased by the court if the father’s income or the child’s needs change.
Arrears	Retroactive support can be claimed from the moment a judicial or extrajudicial demand is made.