SSS:
https://howpo.info/blog/freelancers-guide-sss-how-to-register-and-loan/
https://thefreelancechannel.com/pay-sss-contribution-online/
https://member.sss.gov.ph/members/registrationPages/memberE1.jsp
PHILHEALTH:
https://www.philhealth.gov.ph/members/informal/registration.html
PAG-IBIG FUND:
https://www.pagibigfund.gov.ph/payments.html
BIR:
https://www.taxumo.com/blog/freelance-tax-philippines/