In the Philippines, the legal framework governing children born outside of a valid marriage—referred to legally as illegitimate children—is distinct and specifically outlined in the Family Code of the Philippines and subsequent amendatory laws. Understanding these rights is crucial for both mothers and fathers to ensure the "best interest of the child" is upheld.

1. The Mother’s Primary Rights: Sole Parental Authority

Under Article 176 of the Family Code, illegitimate children are under the sole parental authority of the mother. This is a significant departure from the joint parental authority exercised by married parents.

Legal Implications of Sole Authority:

Custody: The mother has the automatic legal right to keep the child in her care.
Representation: The mother is the legal representative of the child in all matters, including signing contracts or school documents.
Decision-Making: The mother decides on the child's residence, education, and medical care without the legal necessity of the father's consent.

2. The "Tender Age" Rule

The Philippine legal system strongly favors the mother during a child’s formative years. Under Article 213 of the Family Code, no child under seven years of age shall be separated from the mother unless the court finds compelling reasons to do so.

Compelling reasons to deprive a mother of custody include:

Neglect or abandonment.
Physical or psychological abuse.
Drug addiction or habitual drunkenness.
Mental incapacity.
Engaging in "prostitution" or immoral conduct that directly affects the child's welfare.

Note: Poverty alone is not a valid ground to strip a mother of custody. As long as she can provide basic care, the court will generally uphold her right over a wealthier father.

3. The Father’s Rights and Recognition

A father of an illegitimate child does not automatically have parental rights. His rights are contingent upon recognition of paternity.

Recognition of Paternity

A father can recognize a child through:

The Record of Birth (signing the birth certificate).
An Admission of Paternity in a public document.
A Private Handwritten Instrument signed by him.

Rights Granted Upon Recognition:

Surname: Under Republic Act No. 9255, illegitimate children may use the surname of their father if the father has acknowledged them.
Succession: The child becomes a compulsory heir and is entitled to a legitime (inheritance), which is typically half of the legitime of a legitimate child.
Visitation Rights: While the mother has sole authority, the Supreme Court has consistently ruled that the father has the natural right of visitation to foster a relationship with his child, provided he is not a threat to the child's safety.

4. The Duty of Support

Support is a mandatory obligation of both parents, regardless of their marital status or who has custody. Under Philippine law, support comprises everything indispensable for sustenance, dwelling, clothing, medical attendance, education, and transportation.

Aspect	Rule for Unmarried Parents
Obligation	The father is legally required to provide support once paternity is established.
Amount	There is no fixed amount; it is proportionate to the resources of the giver and the needs of the recipient.
Enforcement	If a father refuses to provide support, the mother can file a civil case for support or a criminal case under R.A. 9262 (Violence Against Women and Their Children) for economic abuse.

5. Custody Battles: The "Best Interest" Principle

If an unmarried father seeks custody, he must file a Petition for Habeas Corpus in relation to Custody or a Petition for Custody in the Family Court. He bears the heavy burden of proving that the mother is "unfit."

The court’s North Star in these proceedings is always the Best Interest of the Child. Factors considered include:

The child's health, safety, and moral integrity.
The emotional ties between the child and the parties.
The ability of the parent to provide for the child's needs.
If the child is over seven years old, the court may take the child’s preference into account, though it is not binding.

6. The Solo Parents’ Welfare Act (R.A. 8972 & R.A. 11861)

Unmarried mothers (and fathers who have sole custody) are protected under the Solo Parents’ Welfare Act. Recent amendments have expanded these benefits, which include:

Parental Leave: Seven days of paid leave per year.
Discounts: 10% discount and VAT exemption on baby formula, food, and medical supplements (for those below a certain income threshold).
Cash Subsidy: A monthly subsidy of ₱1,000 for minimum wage earners.
Priority: Preference in low-cost housing and government scholarships.

Summary Table of Rights

Right	Unmarried Mother	Unmarried Father
Parental Authority	Sole	None (unless mother is unfit)
Physical Custody	Automatic	Via Court Order only
Visitation	Grants it	Entitled to it (usually)
Surname Choice	Primary Right	Allowed if child is recognized
Financial Support	Obligated	Obligated