When asked to comment on the $100 limit in IT-470R, para. 9 for benefits conferred on employees at social functions or events, CRA stated:
(a) Where an employer provides a social event or other social activity free of charge to all employees, CRA's policy is that there is no taxable benefit to be included in the income of the employees if the cost per employee for the social event or activity does not exceed $100. The CRA confirms that this is a limit per event and that it is possible that more than one event per year offered by the employer to be covered by this policy. … [T]he number of events to which this policy is applied must remain reasonable … .
(b) Where the party or social event is open to all employees and their spouses, the average cost of $100 will be based on the total number of guests and not just the number of employees.
(c) The $100 limit is an average that is based on the total amount paid by the employer for the function or social event, including room rental, food and entertainment expenses. Therefore, it is necessary to include the GST/QST paid by the employer … .