My two boys are 6 and 3, their dad and his side of the family rarely see them, due to being a bunch of aes! I'm looking to not so much change their surname but add my maiden name to the end... Like a double barreled surname.... I was wondering if to do that i would need my ex's consent too because he is on their birth certificates... Or can i just go on ahead and add them on? Ideally he wouldn't find out until i have done it..... Also does anyone know how much it costs , if anything?? Thanks!!