If you are a dual citizen living in another country and donu2019t file a US tax return, and the US finds out about it, the US government might sue you for millions of dollars just for not filing, even if you owe no taxes at all. See: U.S. sues Vancouver dual citizen for over $1M for not reporting accountsThe penalty is purely for not reporting accounts, not for taxes owing or penalties for unpaid taxes.U.S. citizens (including dual citizens) with signing authority over non-American bank accounts are required to report them, along with the highest amount in the account during the year, on a form called a Report of Foreign Bank and Financial Accounts, or FBAR.Unlike other industrialized countries, the U.S. requires citizens, including dual citizens, to file tax returns no matter where in the world they live.Selling a house and putting the money in a bank account puts the value of the house into the penalty calculation. And moving that money around between different accounts multiplies it, as each dollar is counted several times.The average house in Vancouver is worth more than $1 million, so selling it, and then moving the money around between Canadian accounts can incur insane amounts of penalties from the IRS, which is something most dual citizens are not aware of. Many Canadians have acquired dual citizenship by accident (by being born in a US hospital or having a parent who has American citizenship) and are not aware they are US citizens. Finding out can be a nasty shock for them.The obvious way to avoid this is for dual citizens to revoke their US citizenship, but the US government has made revoking US citizenship nearly impossible. I know people who have been trying to do this for years, with little success. See: Unwilling dual citizens face 10-month wait to shed U.S. citizenship in TorontoUS citizenship has become a real problem for dual citizens residing in Europe because many European banks will cancel their bank accounts and refuse to deal with them because of the enormous complications involved in filing documents with US tax authorities.US citizenship has become like leprosy, it is an affliction nearly impossible to cure without professional help.Hint: Itu2019s much quicker and cheaper for a Canadian citizen to go to Mexico to revoke their US citizenship, because the US government hasnu2019t figured out this dodge around their laws. See: Meet the Alberta man who went to Tijuana to renounce his U.S. citizenship