To apply for a Pag-IBIG loan, you'll need to prepare several documents. Generally, you should have a completed loan application form, proof of income such as payslips or a certificate of employment, and a valid ID. Additionally, you'll need to present proof of Pag-IBIG membership and any relevant property documents if you're applying for a housing loan. It's best to check the Pag-IBIG Fund's official website for the most accurate and detailed requirements based on your specific loan type.