To qualify for senior citizen discount airfare in the Philippines, you need to be a valid Senior Citizen ID holder as issued by the government. Airlines typically ask for this ID at the time of booking or check-in. It’s also important to check with individual airlines as they may have specific policies regarding the application of discounts. Additionally, discounts may apply only to certain flights and are subject to availability, so it’s wise to confirm these details with the airline or visit the relevant government website for more information.