In most of Canada, either partner may informally assume the spouse's surname after marriage, so long as it is not for the purposes of fraud. The same is true for people in common-law relationships, in some provinces. This is not considered a legal name change in most provinces, excluding British Columbia. For federal purposes, such as a Canadian passport, Canadians may also assume their partner's surname if they are in a common-law relationship. In the province of British Columbia, people have to undergo a legal name change if they want to use a combined surname after marriage. Their marriage certificate is considered proof of their new name.