From the namechanges.ca website:
Marriage is the most common reason for changing names. In BC you can take your spouse’s name after marriage or keep your own. A double barrelled surname is where you add your spouse’s surname to your own, either with or without a hyphen.
While other provinces and most BC government agencies allow this, it isn’t possible to have your BC Care Card changed into a double barrelled surname on presentation of your marriage certificate.
Double barrelled surnames require a legal name change certificate issued by BC Vital Statistics. Once you have your legal name change certificate you must commence using your new name immedaitley, regardless of your wedding date.
If after assuming a spouse’s surname after marriage you decide to go back to using your own surname, you can do this at any time without a legal change of name.
Policies and procedures for completing a legal change of name is set out in the Name Act.
BC Legislation
Click here for Legal Name Change details.
Click here to see the Name Act details