For heterosexual married couples, the issue of paternity is quite simple. If a woman has a child, her husband is automatically the legal father. It is different for unmarried couples, however. Then the biological father is not automatically the legal father. To be acknowledged as such, he must officially acknowledge paternity. That is, he must have it publicly recorded with an official governmental agency. Many hetero couples choose to do the paternity recognition (Vaterschaftsanerkennung) before the birth. However, it is also possible to do it any time afterwards. Recognition before birth has the advantage that the father is entered on the birth certificate and in the birth register at the same time. If this happens later, the civil registration office (Standesamt) has to issue a new, corrected certificate, which costs extra.