In 2016, Amazon Prime expanded the availability of its Prime Video service globally. It is now available in over 200 countries and territories around the world. Thus, the streaming service is now available everywhere apart from mainland China, Iran, North Korea, and Syria.
That said, each country’s catalog of titles differs and when you leave your home country on vacation, it is possible that the catalog will be smaller (or different). When traveling abroad, you can check the Watch While Abroad section to see what titles remain available.