Here’s a detailed guide, in article form, on how suspected infidelity intersects with child support, what evidence matters, and what legal steps are available under Philippine law.

I. Legal Basis of Child Support in the Philippines

1. What is “support” under the law?

Under the Family Code of the Philippines, “support” includes everything indispensable for:

Sustenance (food, water)
Clothing
Dwelling
Medical and dental care
Education and transportation
In some cases, even training for a profession or trade

Support is not just “baon” or tuition; it is the basic package of needs for a child to live a decent life consistent with the family’s circumstances.

2. Who is obligated to give support?

The Family Code lists persons legally bound to support one another. For purposes of child support, the most important are:

Parents and their legitimate children
Parents and their illegitimate children
Legitimate ascendants and descendants (e.g., grandparents, if parents truly cannot support)
In some situations, siblings (for support between brothers and sisters)

So long as filiation (the legal parent–child relationship) is established, the parent has a legal obligation to support the child — regardless of marital conflict, infidelity, or separation.

3. Is support optional or negotiable?

No. Support is:

A legal obligation, not a favor.
Demandable when needed.
Proportionate to:
- The resources/means of the parent(s)
- The needs of the child

Parents may agree on the amount and mode (cash, tuition payments, in-kind, etc.), but they cannot legally agree that a child gets no support at all.

II. Infidelity vs. Child Support: What the Law Generally Says

1. Infidelity is a matter between the parents

Infidelity (e.g., adultery, concubinage, or extra-marital affairs) is:

A ground for legal separation.
Potentially a criminal offense under the Revised Penal Code (adultery/concubinage), if the requirements are met.
A moral issue that may affect marital rights.

But it does not erase a parent’s duty to support his or her children. The law treats:

Spousal rights (e.g., spousal support, property relations, moral damages) vs.
Children’s rights (e.g., support, legitime, parental authority)

as distinct. You can be an unfaithful spouse and still be legally bound to provide for your child.

2. Infidelity of the parent seeking support

If you are the parent asking for support and the other parent accuses you of cheating:

Your alleged infidelity does not cancel your child’s right to support.
The other parent cannot lawfully say, “I won’t support the child because you cheated.”
In court, the focus in a petition for support is:
- Whether the respondent is legally a parent of the child.
- The needs of the child.
- The capacity of the parent to give support.

Your personal romantic life may become relevant in custody or legal separation cases, but it is generally not a defense to avoid child support.

3. Infidelity of the parent paying support

If the parent who should be paying support is the one having an affair:

The offended spouse may:
- File a criminal case for adultery or concubinage (subject to specific rules).
- File a petition for legal separation, which can affect property relations and spousal support.
However, this does not reduce or erase their obligation to support their children. In fact, courts may take a firm stance that the unfaithful parent must continue or even regularize child support.

4. Infidelity and spousal support vs. child support

Important distinction:

Spousal support (support for the husband/wife)
Child support (support for the child)

In some situations (for example, in legal separation where one spouse is declared at fault), the guilty spouse’s right to support from the innocent spouse can be affected or even lost.

But child support is different. It is a right of the child, and courts are extremely reluctant to reduce or deny it because of a parent’s misconduct.

III. When Infidelity Causes Doubts About Paternity

The more complicated issue is when suspected infidelity leads the alleged father to question whether the child is his and therefore refuses to support.

1. Presumption of legitimacy (for married parents)

If the parents are married, a child conceived or born during the marriage is generally presumed legitimate. This means:

The husband is presumed to be the father.
He cannot simply refuse support based on “doubts” or rumors.

To challenge this, he must file a proper legal action (an action to impugn legitimacy) under very strict conditions and time limits. It is not enough to just say informally, “Baka hindi ko anak ‘yan.”

Until a final court judgment declares otherwise, the presumption of legitimacy stands, and the child remains entitled to support.

2. Children born out of wedlock (illegitimate children)

For a child born outside marriage, the key is proof of filiation, such as:

Birth certificate listing the father, with his voluntary acknowledgment.
Written acknowledgment in a public document or private handwritten instrument.
Clear and convincing evidence of the father’s open and continuous recognition (e.g., he introduced the child as his, he previously supported the child, etc.).

If the father now denies paternity because he suspects the mother’s infidelity:

The mother may file a case for recognition and support.
The court may, in appropriate cases, order DNA testing or evaluate all evidence to determine paternity.

3. Can a father demand a DNA test before giving support?

In practice:

A father may ask for a DNA test if he has serious doubts.
The court, not the father alone, will ultimately decide if a DNA test is appropriate in a legal case.
While the case is pending, the court may grant support pendente lite (temporary support) if there is enough initial evidence of filiation and need.

IV. Evidence: What Actually Matters in a Child Support Case

When you seek child support, the central questions for the court are:

Is the respondent legally a parent of the child?
What are the needs of the child?
What are the means (income/resources) of the parent?
Has the parent failed or refused to provide reasonable support?

Suspected infidelity is usually background; the core is still filiation, needs, and capacity.

1. Evidence of filiation (parent–child relationship)

Useful documents:

Birth certificate of the child (with parents’ names).
Marriage certificate of the parents, if married.
Acknowledgment documents:
- Affidavit of acknowledgment
- Entries in public documents
Photos and messages:
- Photos showing the parent’s involvement (baptism, birthday parties, family trips).
- Messages where the parent calls the child “anak,” “son,” “daughter,” etc.
Receipts or bank records of previous support:
- This can show both recognition and a history of support.

2. Evidence of the child’s needs

Prepare proof of:

School-related expenses:
- Tuition, books, uniforms, school fees, transportation.
Basic living expenses:
- Grocery receipts, rent (if relevant), utilities proportionally benefiting the child.
Medical and dental expenses:
- Doctor’s prescriptions, hospital bills, maintenance medicines.
Special needs, if any:
- Therapy, assistive devices, etc.

You don’t need to be absolutely exact, but you should show a reasonable picture of monthly expenses.

3. Evidence of the parent’s capacity to pay

You don’t have to know everything about the other parent’s finances. The court can help through subpoenas and other processes. But it’s helpful if you have:

Payslips
Employment contracts
Income tax returns (ITR)
Business permits or business-related documents
Social media or other evidence indicating lifestyle (foreign travel, luxury items) – not decisive alone, but sometimes relevant to show financial capacity.

4. Evidence of refusal or neglect to support

To show that the other parent is failing in their duty:

Save text messages, chats, emails where:
- You request support.
- The parent refuses, ignores, or conditions support (“Hindi kita susuportahan kasi may ibang lalaki ka”).
Record instances and dates when support stopped or was significantly reduced.
If there has been a previous agreement, keep that document and show how it was violated.

V. Practical Legal Steps to Seek Child Support

Step 1: Assess your situation

Ask yourself:

Are we still married, or separated in fact, or never married?
Is paternity admitted or contested?
Is there any existing case (e.g., legal separation, VAWC case, recognition case)?
Am I financially qualified to seek help from Public Attorney’s Office (PAO)?

These affect your strategy, but in all cases, remember: the child has the right to support.

Step 2: Try an amicable arrangement (if safe)

If there is no history of violence or abuse, you may attempt:

A written agreement on support (amount, due date, mode of payment).
You can negotiate:
- Fixed monthly amount.
- Direct payment of tuition, rent, or major expenses.
- Combination of cash + in-kind.

Make sure the agreement:

Clearly names the child.
States the amount and frequency.
Is signed by both parties (and ideally notarized).

However, do not get trapped into accepting an amount that is clearly too low or giving up rights permanently. Agreements cannot waive the child’s legal right to reasonable support.

Step 3: Barangay conciliation (when applicable)

Under the Katarungang Pambarangay Law, many disputes between individuals living in the same city or municipality must pass through the Lupong Tagapamayapa (Barangay mediation) first, before going to court.

This may apply to support disputes if both parties live in the same city/municipality and no exceptions (like imminent violence) apply.
The barangay can help the parties reach a settlement.
A written barangay settlement can be enforced like a court judgment if properly made.

If there is history or risk of violence, especially under RA 9262 (Anti-VAWC), you should prioritize your and your child’s safety and consult a lawyer, PAO, or a women’s/children’s desk at the police or DSWD before engaging in face-to-face mediation.

Step 4: Consult a lawyer or PAO

If friendly settlement fails or is unsafe:

You can consult a private lawyer or the Public Attorney’s Office (PAO).
PAO provides free legal services to indigent persons who meet certain income/asset criteria.

Bring:

IDs and residence details
Child’s birth certificate
Marriage certificate (if any)
Any written agreements or barangay documents
Evidence of the other parent’s refusal to support

Step 5: Filing a case for support (or recognition and support)

If needed, your lawyer may file:

A petition/complaint for support – if paternity/filiation is basically accepted but the parent refuses to support; or
A petition for compulsory recognition and support – if the parent denies paternity and the child is illegitimate; or
Join the request for support in another case:
- Legal separation, annulment, or VAWC (RA 9262) case, where support can be included as part of the reliefs.

The case is usually filed in the Family Court (Regional Trial Court designated as such), generally where you or the child resides.

Support pendente lite (temporary support)

While the case is still ongoing (which can take time), the court may grant support pendente lite, a temporary support order, if there’s enough initial evidence. This ensures the child is not left without support during litigation.

Step 6: Enforcement of support orders

Once the court issues an order or decision:

The paying parent may be required to:
- Pay a fixed monthly amount.
- Pay certain expenses directly (tuition, rent).
- Provide support in kind.

If they do not comply:

Their salary may be garnished (employer ordered to deduct from salary).
Properties may be subject to levy or execution.
They can be cited for contempt of court for willful disobedience of a lawful order.

In certain circumstances, persistent refusal to support, combined with threats or controlling behavior, may also fall under economic abuse punishable under RA 9262.

VI. How Infidelity Might Still Appear in a Support Case

While infidelity itself does not erase child support, it can still appear in related ways:

Custody disputes: Infidelity may be raised to question a parent’s moral fitness, especially if it is shown to directly harm the child (e.g., exposing the child to dangerous environments). However, courts are more concerned with best interests of the child than with punishing moral lapses alone.
Legal separation or VAWC cases: Infidelity of the paying parent may co-exist with emotional or economic abuse. Child support can be one of the orders issued for protection and welfare.
Paternity challenges: Suspected infidelity around the time of conception may be used to argue that the child is not biologically related. But as explained:
- For children born within marriage, strict rules on impugning legitimacy apply.
- For children outside marriage, the court will look at all evidence of filiation and may allow DNA testing.

What’s important: infidelity is not a shortcut to avoid support obligations.

VII. Common Misconceptions and Clarifications

“If you cheated, I don’t have to support the child.” ❌ Wrong. The obligation is to the child. Infidelity does not remove that duty.
“I can stop support anytime if I’m angry or if I think the child isn’t mine.” ❌ Wrong. Until a court says otherwise, the legal relationship remains, especially for children presumed legitimate. Unilateral withdrawal of support can backfire legally.
“Illegitimate children are not entitled to support.” ❌ Wrong. Illegitimate children have a legal right to support from their parents. The amount may follow different rules in inheritance, but support is owed.
“I must first win an adultery case before I can get support.” ❌ Wrong. A child support case is separate. You do not need to file or win a criminal case for adultery/concubinage before demanding support.
“Support must always be 50–50 between parents.” ❌ Not necessarily. Support is based on:
- The needs of the child, and
- The respective means of each parent. If one parent earns much more, that parent can be ordered to shoulder a larger share.

VIII. Determining the Amount of Support

Courts consider:

The standard of living that the child would reasonably have if both parents lived together and fulfilled their duties.
The actual income and resources of each parent.
Any special circumstances (health conditions, special education, etc.).

Support is:

Adjustable – If the parent loses or gains significantly more income, or if the child’s needs change (e.g., entering college, serious illness), either party can ask the court to increase or decrease support.
Often paid monthly, but may also include lump-sum payments for specific major expenses (e.g., one-time tuition, hospitalization).

IX. Practical Tips for Parents in This Situation

Separate emotions from legal rights. Anger about infidelity is understandable, but the law separates spousal betrayal from children’s rights.
Document everything. Keep copies of:
- Birth certificate, marriage certificate.
- Receipts and bills related to the child.
- Messages asking for support and responses.
Do not refuse support as “revenge.” Using the child’s support as a weapon will likely harm you legally and your child practically.
Prioritize safety in abusive situations. If the infidelity situation involves threats, violence, or severe emotional abuse, consider:
- RA 9262 protections (protection orders, custody, support).
- Help from barangay, DSWD, women’s desk, or shelters.
Seek professional legal advice. This article provides general information, not individualized legal advice. Facts differ from case to case, and small details can change the legal outcome.

X. Summary

Child support is a right of the child, anchored in the Family Code.
Suspected or proven infidelity of either parent does not extinguish the obligation to support the child.
Infidelity becomes relevant mainly in:
- Spousal rights (legal separation, criminal cases).
- Custody disputes (if it affects the child’s welfare).
- Paternity disputes (if the alleged father questions filiation).
To enforce child support:
- Gather evidence of filiation, needs, capacity, and refusal.
- Try amicable settlement or barangay conciliation if safe.
- If needed, file a court case for support or recognition and support.
Support orders can be enforced through garnishment, execution, and contempt, and may be related to VAWC in cases of economic abuse.

If you’re personally dealing with this situation, it’s important to talk to a lawyer or PAO who can look at your specific facts and help you craft a strategy that protects both your rights and, most importantly, your child’s future.