To avail of senior citizen discounts at hotels in the Philippines, you typically need to present your valid Senior Citizen ID issued by the government. The hotel may also require you to show proof of your booking, such as a reservation confirmation. It's good practice to check with the specific hotel in advance as policies may differ, and some hotels have additional requirements. If you're uncertain, consider contacting the hotel directly or visiting the official government website for more detailed guidance on discounts available to seniors.