Charles III and Japanese Imperial couple exempt from passport requirements

Only three individuals in the world are permitted to travel internationally without a standard passport: King Charles III of the United Kingdom, and Emperor Naruhito and Empress Masako of Japan.

According to the official website of the British Royal Family, the King does not require a British passport because passports are issued in his name. Instead of a regular passport, a special document is used to request that the holder be allowed free passage without hindrance and be provided with necessary protection and support. While the King holds this privilege, other members of the British Royal Family, including Prince William and Queen Camilla, must use standard passports.

Similarly, the Japanese Emperor and Empress hold a unique status that exempts them from standard passport requirements, a distinction noted in historical ministerial documents.