NO.  See CRA note below for more information.
Does a registered charity have to issue official donation receipts for gifts it receives?
• No.  Receipting carries with it a certain administrative burden, and receipted donations increase a registered charity’s spending obligation. Therefore, registered charities may choose to issue receipts according to certain criteria, or they may choose not to issue receipts at all.
• Some registered charities set minimum donation thresholds for receipting. Others do not provide receipts during certain fundraising events.
• Remember that donors cannot claim a charitable tax credit or deduction unless they are issued an official donation receipt. Therefore, registered charities are strongly advised to make potential donors aware of any circumstances in which a receipt will not be issued.
Related topics
• What is a gift?
• CSP-R02, Receipt