How Long Should you keep your tax stuff?

Who has to keep books and records?
3. For the purpose of this circular, person has the meaning assigned by subsection 248(1) of the Income Tax Act (the Act). Therefore, in addition to individuals, a “person” in this context includes a corporation, a trust, and any exempt entity listed in subsection 149(1) of the Act such as a registered charity, a registered Canadian amateur athletic association, and a non-profit organization.
4. Books and records must be kept by every:
person carrying on a business;
person who is required to pay or collect taxes or other amounts according to the acts mentioned in paragraph 1 above;
registered charity or registered Canadian amateur athletic association; and
registered agent of a registered political party or an official agent for a candidate in a federal election.

How Long?
26. Under the Act, books, records, and their related accounts and source documents, other than those referred to in paragraphs 27 and 28 below, have to be kept for a minimum of six years from the end of the last tax year to which they relate. The tax year is the fiscal period for corporations and the calendar year for all other taxpayers. Under the Employment Insurance Act and Canada Pension Plan, the retention period begins at the end of the calendar year to which the books and records relate.