I am wondering what the law is when it comes to using a different names than what is on our birth certificate. My friend has called her son a different name to what is on his birth certificate. This is because the father left and as she wasn't married and didn't want her son to have a different name to her and her other child. So he is known in the school by her surname. She says there is no law and that you can call yourself or your children what u like as long as your not doing it to de fraud. His bank and doctors all know him by her surname. She says it's only when booking holidays she has to use his real name as his passport has his birth name on it. Is this correct?