"You must contact us immediately in writing when your file data changes. You should advise us immediately of a change of your residential or mailing address, marital status (that is engagement, marriage, common-law relationship, divorce, separation, etc.), pregnancy, birth of a child, change of employment, etc. We need this information in order to inform you quickly about any necessary further steps that must be followed. Your timely response will allow us to avoid possible file processing delays. We will not acknowledge receipt of these changes, but will contact you if any action is required."http://www.canadainternational.gc.ca/russia-russie/visas/application-demande.aspx?lang=eng