In 2026, while mobile boarding passes are accepted at the vast majority of international airports, it is still highly recommended to carry a paper backup. Most major airlines provide a digital QR code via their app that you can scan at security, duty-free, and the boarding gate. However, certain countries and specific airports (particularly in parts of Asia, Africa, and South America) still legally require a physical paper pass for immigration "stamping" or for security records that the digital version cannot accommodate. Additionally, technology is not infallible; a dead phone battery, a cracked screen that won't scan, or a lack of airport Wi-Fi can prevent you from accessing your digital pass at a critical moment. Some low-cost international carriers also charge "check-in fees" at the airport if you don't arrive with a pre-printed pass. To be safe, you should check in online to secure your seat and download the mobile version, but then print a hard copy at home or at an airport kiosk. This "belt and braces" approach ensures that even if your phone fails or you encounter a "low-tech" security checkpoint, you have the one document required to legally board the aircraft.