When marrying brides and grooms have the right to:
- keep their single name
- use their spouse's name
- use a combination of the two.
If you decide to change your name there is no need to do anything official, you simply assume your new name.
Both your single and married names are legal names and in theory you could use both, however Births Deaths & Marriages recommend that you choose one and stick to it (easier if you want to use your passport for id, etc.).
You will need your marriage certificate in order to change your name on your passport, at the bank, etc., so you won't be able to do this until after you're married. Then you can organise the changes at your leisure.
You can travel on a passport in your single name, however you must make sure that your tickets are issued in the same name.
If, later on, you decide to change the name on your passport you can either have it endorsed, or apply for a new passport.
What's in a name? That which we call a rose
By any other name would smell as sweet.
William Shakespeare. Romeo and Juliet
If you want to change your name, get in touch with The Department of Internal Affairs. They have a good website which has plenty of information, including all of the applicable forms and fees. View their website here.