The full definition of what constitutes a non-qualified or prohibited investment is quite comprehensive and the consequences of making a mistake are severe. Taxpayers should be extremely weary of making any investment in a TFSA if they are closely connected with the investment or if the investment is in a private business and consult with an experienced Toronto tax lawyer prior to proceeding with the plan.
In the event that you think you may have made a non-qualified or prohibited investment or if CRA has assessed you as such in a tax audit, it is highly recommended that you speak with an expert Canadian tax lawyer regarding whether any steps can be taken dispute whether there was a non-qualified or prohibited investment or apply for discretionary relief.