I was told when I applied for my U.S. passport years ago that as long as I had never worked in the United States and did not have a SSN, then I did not have to file taxes. This is what the U.S. Consulate told me at the time.
I am now hearing that this is not the case.
As a U.S. citizen living in Canada, what am I supposed to be doing about U.S. income tax?
As a U.S. citizen — regardless of how you became one, or where you currently live — you must file a U.S. income tax return each year. Your worldwide income must be declared on your U.S. income tax return.
I found a document on the subject, "U.S. Citizens Living in Canada" [PDF], from BMO's full-service broker, BMO Nesbitt Burns. Here's a notable excerpt:
1) I am a US citizen living in Canada. What are my income tax filing and reporting requirements?
US Income Tax Returns – A US citizen residing in Canada should be filing a US individual income tax return (Form 1040) to report worldwide income on an annual basis, in addition to the Canadian income tax return filed as a tax resident of Canada. Although income is reported in both Canada and the US, double taxation is generally mitigated through the use of foreign tax credits. The foreign tax credit mechanism allows for any Canadian income tax paid to reduce the amount of US income tax otherwise payable on the income that is taxable on both the Canadian and US income tax returns.
FBAR Reporting – In addition to the filing of annual US income tax returns, there are a number of information reporting requirements for US citizens. One of the requirements is a Report of Foreign Bank and Financial Accounts (FBAR), Form TD F 90-22.1, which must be filed if you have a financial interest (or signature authority) in one or more accounts in a foreign country and the aggregate value of those accounts exceeds US$10,000. While there are significant penalties (in addition to possible criminal prosecution) associated with the failure to file individual income tax returns and complying with the FBAR reporting requirements, the IRS has indicated that penalties may be waived if the failure to file the FBAR or a US individual tax return is due to a reasonable cause. Beginning in 2014, under the new Foreign Account Tax Compliance Act (FATCA), non-US financial institutions will be required to identify and report on accounts held for US citizens.
The above information about a U.S. citizen's obligation to file was taken from page 1, but the document contains additional information relevant to U.S. citizens living in Canada, such as how RRSP, TFSA, and RESP accounts are treated, etc. I suggest you give it a read.
You should also seek the advice of a professional in Canada & U.S. cross-border taxation.
You were told wrong. As a US citizen, you're expected to file your tax return regardless of where you live. If you're under filing obligations (income above the exemption+deduction level, basically), or if you claim treaty or other benefits (for example to exclude foreign earned income or RRSP) or you must file form 8938 or FBAR - you must file your tax return, even if no tax is due (for FBAR - see Schedule B at the bottom, there's a checkbox to check).
In addition you must file FBAR about all of your foreign accounts, if your aggregate balances are above $10K (USD) at any time during the year.
See here for more information: IRS Publication 54.
Not only must you file, but in many countries you must declare your status as a "US person" to your bank for FATCA reporting.
Even with a US Passport you may have trouble entering if you are not squared off with the IRS.
