To start an online selling business in the Philippines, you'll need to register your business, which can be done through the Department of Trade and Industry (DTI) for sole proprietorships or the Securities and Exchange Commission (SEC) for partnerships and corporations. Additionally, securing a Barangay clearance and a business permit from your local government unit is essential. It's also wise to set up a reliable payment method and consider registering for taxes with the Bureau of Internal Revenue (BIR). Always check the latest government guidelines or consult with a local expert to ensure compliance with regulations.