There’s no way around it, a business’ tax records can take up an enormous amount of room. Also, you may want to destroy your old records for security or other purposes. The Canada Revenue Agency has strict guidelines when it comes to keeping and destroying tax records. Their guidelines state: You must keep all of the records and supporting documents that are required to determine your tax obligations and entitlements for a period of six years from the end of the last tax year to which they relate.