In Canada, you are required to submit income tax returns for the current year, plus any years that you have neglected to file. You will need to have all income records (T4 and T5 forms) for every year or at least be able to prove your level of income during the years you did not file. The same goes for any deductions you want to make. Since your employer may have deducted federal and provincial income taxes, employment insurance (EI), pension benefits (CPP or Québec), fees for provincial medicare programs (BC, AL, ON), and any other items from your income over the period you did not file, it is important to have this information on hand. For example, if there is no record that you and your employer contributed to EI, you cannot file a claim with them if you find yourself out of work. You will be required to pay any taxes and other mandatory deductions that you would have paid over the ten year period in question. It is very important for you to collect all the required documentation, because it is likely to work in your favour. However, if you owe back taxes, you will be assessed late fees and interest. If the amount is substantial, they may allow you to make periods over a period of time. If you don't go through this process now, you will have to do it at some future date. Better to get the pain over now, while you may still be able to obtain and remember such information. There is a real benefit in using a tax accountant or an income tax service when you file all of this paperwork, because they are in a good position to know what is needed and how everything needs to be done. As a side-note, one of my step-children failed to file for several years and went through this process. He received a refund, because of educational expenses and from overpayments of income taxes at source during the period. You have a 50-50 chance you will come out ahead. The chances go up sharply if you were a full-time student during the affected period.

Is there a reason, you have not filed an income tax in 10 years? the internal revenue service may be looking for you. In this case, you will need an attorney. But, if you did not qualify or was not required to file an income tax for the last 10 years, you should contact a cpa(certified public accounant). this person can educate you on the latest deductions, interest rates, qualifications and general tax information you need. cpas are located in the yellow pages of the phone book.