If your annual income is more than US$10,000 (or $400 self-employed), you must file a form 1040. While any tax due is still due on April 15th, expats get an automatic filing extension until June 15th. This can be extended still further until October 15th.
If you live abroad and have assets worth over US$200,000, you also need to file a form 8938 declaring them.
“A 2013 survey commissioned by Thomson Reuters asked 1,009 Canadians if they liked filing their taxes. 41 per cent said yes.”
– CBC News
If you have more than US$10,000 in total in one or more foreign bank accounts at any time during the tax year, you also need to file FinCEN form 114, sometimes known as an FBAR (Foreign Bank Account Report).
If you are paying income tax in Canada, there are several ways to avoid paying tax on the same income to the IRS. The two primary ones are the Foreign Earned Income Exclusion, which allows you to exclude the first around US$100,000 from US income tax if you can demonstrate that you are resident in Canada, and the Foreign Tax Credit, which gives you a dollar tax credit for every dollar of tax you’ve paid in Canada.
The Foreign Tax Credit is typically a better option if you pay more tax in Canada than you would owe in the US, as you can carry the excess tax credits forward for future use. Don’t forget though, even if you don’t owe any tax in the USA if your income is more than US$10,000 (or $400 self-employed) you still have to file a return.
The US and Canadian governments share taxpayer info, while Canadian banks pass on their US account holders’ account info to the IRS, so it’s not worth being economical with the truth or burying your head in the sand. The penalties for tax evasion for expats are stringent, to say the least.
If you’re a US citizen or green card holder (including dual citizens) and you have been living in Canada for some time but didn’t know you had to file a US tax return, don’t worry: there’s a program called the IRS Streamlined Procedure that allows you to catch up on your filing without paying any fines. It’s better to do this soon though before the IRS comes to you.