Paternity law refers to the legal relationship between a father and his biological or adopted [child]ren and deals with the rights and obligations of both the father and the child to each other as well as to others. A child's paternity may be relevant in relation to issues of legitimacy, inheritance and rights to a putative father's title or surname, as well as the biological father's rights to child custody in the case of separation or divorce and obligations for child support.
A child born to a married woman is presumed under common law to be the child of her husband by a "presumption of paternity" or presumption of legitimacy. In consideration of a possible non-paternity event (which may or may not include paternity fraud) these presumptions may be rebutted by evidence to the contrary, for example, in disputed child custody and child support cases during divorce, annulment or legal separation.
In the case of a father not married to a child's mother, a man may accept the paternity of the child in what is called a "voluntary acknowledgment of paternity", the mother or legal authorities can file a petition for a determination of paternity against a putative father, or paternity can be determined by the courts through estoppel over time. Today, when paternity is in dispute or doubt, paternity testing may be used to conclusively resolve the issue.
Generally, under common law, a biological father has a legal obligation for the maintenance or support of his biological offspring, whether or not he is legally competent to marry the child's mother.
In jurisdictions where there is no presumption of paternity there is a process for fathers to recognise their children and become the legal father of the child. partenity also determine the issues of legitimacy, maintanance, custody and guardianship.
Where paternity of the child is in question, a party may ask the court to determine paternity of one or more possible fathers (called putative fathers), typically based initially upon sworn statements and then upon testimony or other evidence.
A successful application to the court results in an order assigning paternity to a specific man, possibly including support responsibility and/or visitation rights, or declaring that one or more men (possibly including the husband of the mother) are not the father of the child. A disavowal action is a legal proceeding where a putative father attempts to prove to the court that he is not the father; if successful, it relieves the former putative father of legal responsibility for the child.
On the other hand, it could be the case where several putative fathers are fighting to establish custody. In such case, in the US, because of the Supreme Court ruling in 1989, Michael H. v. Gerald D., the mother's legal husband takes precedence over the others, even if he is not the biological father.
In the United States, a divorcing father files a parenting plan with a district court which outlines how the parents will share responsibilities on matters such as custody, visitation, support and insurance.
Some paternity laws assign full parental responsibility to fathers even in cases of women lying about contraception, using deceit (such as oral sex followed by self-artificial insemination or statutory rape by a woman (Hermesmann v. Seyer).
If the context of inheritance rights, it will be the heirs of the deceased person who are attempting to dispute or establish paternity. In some states, DNA testing will be dispositive to establish paternity. In most states, however, there are a variety of rules and time restrictions that can deny inheritance rights to biological children of a deceased father.