This would involve testing the child and the father to see how closely related their DNA is.
It is when the father disagrees that legal action will need to be started in order to establish the legal father of the baby. The mother will need to understand that once the legal action is begun, the court will have a part in the after effects of the paternity testing. If the suspected father is named the biological father, there will be child support hearings and possible custody hearings to contend with in the future.
In regards to the paternity testing, the mother will contact a lawyer who will draft the paternity case. When the case is submitted to the court, a document will be served to the suspected father ordering him to submit a sample via an approved paternity testing facility for biological testing. If the father does not comply with the court order, legal action can be taken against the father up to and including jail time served.
Fathers also have the right to request and / or demand paternity testing. In these cases, they are often confident they are the father of a child and want legal rights in regards to parenting that child. The father can obtain a lawyer and the same process will be completed but with the mother named as the defendant. After the results of the paternity test have definitely named the biological father as claimed, the court will allow child custody hearings to take place.