According to Republic Act No. 9225 (RA 9225), also called the Citizenship Retention and Re-Acquisition Act of 2003, a natural-born Filipino – a person born in the Philippines or born to a Filipino parent – who lost his Philippine citizenship because of naturalization as a citizen of another country can apply for dual citizenship. This law states that former Philippine citizens didn't actually lose their Philippine citizenship under the conditions of the act. This allows them to keep both their naturalized citizenship from a foreign country and their Philippine citizenship.
The petitioner must apply at the Bureau of Immigration if in the Philippines or the nearest Philippine Foreign Post if in a foreign country. He must show proof of being a natural-born Filipino citizen by submitting a National Statistics Office-authenticated copy of Philippine birth certificate. The NSO is the Philippine government's major statistical agency responsible in collecting, compiling, classifying, producing, publishing and disseminating general-purpose statistics and issuing Philippine birth certificates, death certificates, certifications of nonmarriage and marriage certificates.
For a natural-born Filipino born abroad, he must submit an original copy of the Report of Birth issued by the Philippine Foreign Post and the birth certificate issued by competent foreign authorities. The petitioner must also show to the evaluating officer the following documents: old Philippine passport, voter's affidavit or voter's identification card; marriage contract indicating the Philippine citizenship of applicant (if applicable); and other supporting documents that can show the person is a former natural-born citizen of the Philippines.
The petitioner must also submit a photocopy of the certificate of naturalization as a citizen of another country and the current foreign passport. In absence of these documents, he must submit an affidavit explaining the circumstances of acquisition of foreign citizenship. Other requirements include three recent 2-inch-by-2-inch photographs of the applicant, showing front, left-side and right-side views over a white background; proof of address; one-time fees for application processing and issuance of identification certificate; and signed Oath of Allegiance to the Republic of the Philippines. In specific cases where there is reasonable ground to do so, the evaluating officer may also require the submission of additional documents.
Children of Dual-Citizenship Petitioners
The law also covers a child with a foreign passport as long as one of the parents is Filipino. For dual recognition of a child (legitimate, illegitimate or adopted child who is under 18 years old) with foreign citizenship, acquisition of dual citizenship applies at the same time the mother or father reacquires Philippine citizenship. In this case, the petitioner must include the child as beneficiary in the dual-citizenship application. Appropriate fees must also be paid. Document requirements include the copies of the child's birth certificate and foreign passport along with all the documents required from the petitioning parent.