If the Canada Revenue Agency believes some of the information on your tax return is incorrect, the agency will issue a reassessment. The reassessment outlines the mistake and the amount of additional tax owed. If you disagree with the reassessment, you have 90 days to file a Notice of Objection using CRA form T440A. In most cases, the CRA issues a reply to your objection, and if you and the CRA still disagree, the case goes before the Tax Court of Canada. Based on the amount under dispute, appeals go through a general or informal procedure. Both procedures involve similar steps, but the latter is simpler and less formal. As of 2017, disputes worth less than $25,000 for income tax and less than $50,000 for GST fall into the informal category, while disputes concerning greater amounts of money are subjected to the general procedure. As an individual or a sole proprietor, you may represent yourself in both general and informal procedures. If your business is a corporation, you need special permission to represent yourself in general procedure cases. Without that permission, you have to hire a tax attorney. Self-representation in tax court can help you save money. Unless you are experienced with the Tax Court of Canada, you may only want to represent yourself in informal procedures. Dealing with the paperwork and formality requirements of the general procedure can be complicated without the help of a tax lawyer.