Paternity rights can be a hotly debated issue, especially when the father is unmarried or he and the birth mother aren't in a committed relationship. In the United Kingdom, the issue has a number of laws regarding the issue of unmarried father's rights, but there are still stipulations that parents need to know about.
One of the biggest considerations that unmarried fathers will have to keep in mind regarding their rights is when their child was born. If a child was born to an unmarried couple before 2003 the father has no automatic paternal rights, period. The United Kingdom has since altered the automatic rights that fathers are given, and unmarried fathers after the year 2003 are given the same paternal rights as married fathers regarding having a say in their children's lives, visiting rights, permission forms for underage children, etc.
For unmarried fathers whose children were born prior to 2003, there is a way to get father's rights. You need to petition the court for a parental responsibility agreement, which is signed by the father and the mother before being made official by the court. The document, once it's made official, gives an unmarried father the same paternity rights as a married father. This includes all of the rights mentioned above, such as a say in the child's education and health, granting permission for joining the army or leaving the country and other rights parents have by law.
If the parents are still living together in the United Kingdom, they are often considered to have the parental rights they would have if they were married. If the parents are in a civil partnership the law treats them as married for the purposes of conveying parents' rights. It's only after that partnership dissolves and the parents no longer live together that the issue of a father's rights come into play. Once again though, if the child is born after 2003 the physical split doesn't negate any of the father's rights.