Whether you are mandated to file tax or not depends on whether you owe tax to the government. If you don’t, you may not need to file tax returns. Nevertheless, there are a few other aspects that influence your return filing compulsion. 

• If you are expecting a tax refund then it is obvious that you need to file taxes. You would not find CRA on your heels if you don’t owe them. If you want your tax refund, you will have to do it yourself. 
• If you are eligible and want to enjoy government benefits including GST/HST credit, Canada Child Benefit, and GIS or allowance benefit, then you need to file returns. 
• If you have an open Home Buyer’s Plan or Lifelong Learning Plan account through your RRSP, you may need to file a return.
• If you are a contributor to the Canada Pension Plan, you may need to file a return.

There are a few other cases where you might have to file a return even if you don’t owe any taxes. If you find yourself in doubt, it is better to file a return. You can find many cheap or even free options for filing returns