By Court Order
In the absence of any agreement, you will need to apply for a court order to get parental responsibility. You need to be connected to the child, such as their father, step-parent or 2nd female parent. Where you are in a same-sex relationship, the law is not very straightforward (or logical) at the moment, so we suggest speaking to us to find out where you stand, particularly if you are a gay man and considering conceiving with a lesbian couple.
Where a Child Arrangement order for residency is made in favour of the father and he does not have parental responsibility, the court must make a parental responsibility Order for him.
On an application by the father, parental responsibility will normally be granted, unless there is good reason not to, such as the father only seeking this to be able to harass the mother. The court considers the degree of commitment the father has shown or has sought to show to the child when reaching its decision.