Do you have to have your SS or SIN card to cash out a bigger ticket? I know my number and NEVER ever carry my SIN card with me anywhere. I keep it in a lock box. That is what i was also told to do my human resource office because of how much people can do with it. I would prefer not to have to take it if i don't have too. Will they just take your word for it that you know your # or do you have to give them proof?