Best photos of September 4: From an airshow in Egypt to a winding road in Switzerland

Americans living abroad file taxes with the Internal Revenue Service, which can cost hundreds of dollars to complete even though about 60 per cent do not owe taxes, according to the Taxpayer Advocate Service
Those obligations apply to millions of Americans residing overseas – estimates range from 3.9 million to 5.5 million – including so-called "accidental Americans" who are unaware they hold dual citizenship
The double taxation policy has been a contentious issue for decades, with many overseas Americans feeling that it punishes them for pursuing opportunities abroad
Unlike most countries, the US follows a citizenship-based taxation system, meaning that Americans must file taxes annually, even if they do not earn any income in the US.

The National picks the most striking images from around the world