My Ex's surname is on my son's birth certificate as we were together at the time. He left when my Son was 6 wks old and had contact until my son was a year old. My ex then made it clear he didn't want to know and hasn't seen him since. My son is now 7, can I just change my son's legal surname to mine without his biological father's consent?
Yes you canm as your surname is on his birth certificate, but he was registered legally with his surname being that of his Dad, and so you can call him what you want but it would not be legal without going throuh a legal change of name, which, as the father is on the birth cert has to have his approval. My grandson was registered with both his parents names in double-barrel format and so he can choose to use either or both.