In the Philippines, the right of a child to receive support is a matter of public policy and is considered indispensable for their survival and well-being. Under the Family Code of the Philippines, support comprises everything indispensable for sustenance, dwelling, clothing, medical attendance, education, and transportation, in keeping with the financial capacity of the family.

When a parent fails to voluntarily provide these necessities, a legal action for compulsory child support may be filed. To succeed, the petitioner must present specific evidence to establish the legal obligation and the appropriate amount of support.

1. Proof of Filiation

The most critical element in a support case is proving that a parent-child relationship exists. Without establishing filiation, there is no legal basis for a support obligation.

For Legitimate Children: A certified true copy of the PSA Birth Certificate listing the father and mother, along with a Marriage Certificate of the parents.
For Illegitimate Children: * Birth Certificate: Signed by the father at the back (Affidavit of Admission of Paternity).
Written Admission: Any public document or a private handwritten instrument (e.g., letters, diaries, or cards) where the father expressly recognizes the child as his own.
Open and Continuous Possession of Status: Evidence that the child has been treated as the parent’s child in public, such as family photos, school records listing the parent, or testimony from neighbors and relatives.
DNA Testing: Under the Rule on DNA Evidence, a court may order a DNA test. A high probability of paternity (usually 99.9% or higher) serves as conclusive proof of filiation.

2. Evidence of the Child’s Needs

Support is not a fixed amount; it is proportional to the necessities of the child. You must quantify how much is required for the child’s monthly upkeep.

Educational Expenses: School registration forms, tuition fee assessments, and receipts for books, uniforms, and school supplies.
Medical Requirements: Receipts for vitamins, medications, and records of regular pediatric check-ups. If the child has special needs or a chronic condition, medical certificates and therapy invoices are vital.
Daily Sustenance: A breakdown of monthly grocery expenses, milk/formula costs, and utility bills (electricity, water, rent) prorated for the child’s share.
Transportation: Records of school bus fees or daily commute costs.

3. Proof of the Respondent's Capacity to Pay

The amount of support is also dependent on the "means of the giver." The court will not mandate an amount that the parent cannot realistically afford, but it will also not allow a parent to feign poverty.

Employment Records: Payslips, Income Tax Returns (ITR), or a Certificate of Employment (COE).
Business Interests: SEC or DTI registration papers if the parent owns a business, or evidence of lifestyle (e.g., social media posts showing luxury travel or assets).
Properties: Transfer Certificates of Title (TCT) or Tax Declarations for real estate owned by the respondent.
Bank Statements: If available, or a motion to the court to subpoena bank records in specific circumstances.

4. Evidence of Demand

While the right to support is inherent, many courts look for evidence that a formal demand was made before the case was elevated to litigation.

Demand Letter: A formal letter sent via registered mail (with a return card) or personal service, demanding the payment of support and documenting the respondent's refusal or failure to comply.
Katarungang Pambarangay Certificate: In most cases, a Certificate to File Action from the Barangay is required to show that mediation was attempted but failed (unless the parties reside in different cities/provinces or there are urgent grounds for a protection order).

The "Judgment Immediato" and Support Pendente Lite

Because a child cannot wait for the conclusion of a long legal battle to eat or go to school, the petitioner can pray for Support Pendente Lite (support during the pendency of the case).

Legal Note: To obtain this, the petitioner must present "prima facie" (at first sight) evidence of filiation. Once the court sees a clear link between the parent and child, it can issue a provisional order for support while the main case is being heard.

Summary Table: Evidence Checklist

Category	Primary Documents
Legal Bond	PSA Birth Certificate, Marriage Contract, DNA Results
Child's Needs	Tuition receipts, Medical records, Grocery bills, Rent/Utility bills
Parent's Capacity	Payslips, ITR, Business permits, Vehicle/Property registrations
Prior Effort	Formal Demand Letter, Barangay Certificate to File Action