MANILA - Some 5 million Filipinos nationwide remain unregistered with Philippine Statistics Authority (PSA), the agency said Wednesday.

PSA Assistant National Statistician Ronaldo Taghap said almost 40 percent of the total unregistered Filipinos are children aged 0-14 years old.

In 2015, the PSA recorded a total population of more than 100 million Filipinos.

"Hindi nila binigyan halaga yung registration, cultural yun. Political, maraming towns na hindi pa strong and stable ang registering officers. Geographical din pag masayado malayo, walang pera," Taghap said.

(Either they don't see the importance of registration; there are towns where officers aren't well-trained; and some areas are too far and these people don't have money.)

In a forum Wednesday, Childs Rights Network said the largest number of unregistered Filipinos are found in Muslim communities and indigenous population groups.

According to Plan International, around 970,000 ARMM residents do not have birth certificates.

Pauline De Guzman of Plan International emphasized the importance of birth registration.

"It's a legal acknowledgment. A right to their identity. Without a legal identity, the child is invisible to the eyes of the government," she said.

De Guzman said that without a birth certificate, children will not be able to enroll in school and travel overseas.

A birth certificate is also vital for marriage, insurance and securing a voter's ID, gaining access to employment, inheritance, insurance and other social and health services.

"Every child has to have a name and nationality," Connie Salcedo of the Council for the Welfare of Children stressed.

The PSA also urged local government units (LGUs) to implement mobile registration, especially in far-flung areas.

"Wala pa siya sa batas eh. Sana dapat mandatory siya na the LGUs they should budget a certain amount of money to implement mobile registration," Taghap said.

Seven bills pushing for a universal civil registration are still pending in Congress.

"Digitization. That's what everyone is looking forward to, because with the disasters that has happened in the past," said Ifugao Rep. Teddy Baguilat, author of civil registration and vital statistics bill.