Hi everyone! I am a U.S. citizen, and I'm planing to work in Ho Chi Minh city, Vietnam. As I have researched, even though working abroad, the U.S. citizens still have to pay IRS tax return. Therefore, I want to know whether there are any official offices in Ho Chi Minh city that helps the U.S. citizens to file their IRS return tax from Vietnam. And how can I pay the IRS tax? ( paying online by using credit/ debit cards? ) Thank you very much for your information.