Redrupp v. The Queen, 2004 DTC 3320, 2004 TCC 640 -- summary under Evidence

The taxpayer, who was a senior partner of Pricewaterhouse, stated that he followed a practice of recording from invoices substantial expenses that he incurred in order to earn his professional income (amounting to approximately one-half thereof), and then threw away the invoices and detailed support when he received his initial assessment for the year in question. Mogan J. noted that the taxpayer should have retained relevant invoices and receipts for a reasonable time (perhaps the three-year normal reassessment period) and disallowed most of the expenses. Mogan J. also noted (at p. 3325) that "there has been a long-established practice of writing the name of the client or guest on the credit card receipt. a private club voucher or ticket (game or theatre) when a person is entertained".