Legal Definition of Parental Responsibility
Parental Responsibility is defined by of The Children Act 1989 s.3(1) as "...all the rights, duties, powers, responsibilities and authority which by law a parent of a child has in relation to the child and his property".
What it means practically speaking
Regrettably, the legal definition of Parental Responsibility in The Children Act 1989 s.3(1) seems to focus as much on the rights and powers by law which a parent has in relation to a child as it does on a parent's duties and responsibilities. The way the courts regard Parental Responsibility is actually very different to how it comes across in The Children Act 1989. Just as its name suggests, the courts regard Parental Responsibility as the status or label of being a responsible parent to a child, rather than regarding someone who holds Parental Responsibility as necessarily having any particular power to control the care of that child on a day to day basis.
What Power over the Child's Care does Parental Responsibility Give?
Often mothers involved in Children Act proceedings are anxious about the consequences of the biological father obtaining Parental Responsibility for the child. It is important to note that the father obtaining Parental Responsibility will not enable the him to alter the day-to-day care of the child in contravention of the mother's wishes as to how the child is to be cared for.
Parental Responsibility is not a right which empowers one parent to override the decisions of the other. Neither does Parental Responsibility say where the child is to live, or to go to school. Parental Responsibility does not in itself allow a school or a hospital to release the child into the care of a parent who has Parental Responsibility against the wishes of the parent who has day-to-day care of the child or who has a Residence Order. Parental Responsibility does not determine whether a parent has contact with a child or how often he or she will see him.
The High Court made clear in the case of Re P (A Minor) (Parental Responsibility Order)  1 F.L.R.
"It is important to be quite clear than an order for parental responsibility to the father does not give him a right to interfere in matters within the day-to-day management of the child's life. It is to be noted that on any view an order for parental responsibility gives the father no power to override the decision of the mother who already has such responsibility: in the event of disagreement between them on a specific issue relating to the child, the court will have to resolve it. If the father were to seek to misuse the rights given him under s.4 such misuse could, as a second to last resort, be controlled by the court under a prohibited steps order against him and/or a specific issue order. The very last resort of all would presumably be the discharge of the Parental Responsibility order."
So in summary, if two parents who have Parental Responsibility for a child disagree about the care of the child, the parent who has the day-to-day care of the child cannot be stopped from caring for the child in the way they feel is in that child's best interests simply because the other parent has Parental Responsibility. For example, if a father acquired Parental Responsibility, he would have no automatic authority to change the child's school, G.P. or name without the consent of the mother and he would still have to go to court to obtain a Specific Issue Order to make those changes to the child's life.
As it says in The Children Act 1989 s.2(8): "The fact that a person has Parental Responsibility for a child shall not entitle him to act in any way which would be incompatible with any order made with respect to a child under this Act". "Any order" includes the orders under The Children Act 1989 s.8, i.e. Residence Orders, Contact Orders, Prohibited Steps Orders and Specific Issue Orders.
The effect of that is, for example, where a child lives with the mother and the absent father has Parental Responsibility. If the court makes a Prohibited Steps Order forbidding the father from collecting the child from school, maybe because he has threatened to do so, the fact that the father has Parental Responsibility does not entitle him to collect that child from school thereby ignoring the PSO.
What is the Benefit of Having Parental Responsibility?
Most Fathers rightly seek Parental Responsibility for their children for the following reasons:
it is important to have someone capable of exercising Parental Responsibility to consent to medical treatment for the child in the event that the parent with day-to-day care is not available, during contact, day-trips or even in the event of the mother becoming incapacitated;
the status or label of parenthood is important for the bond between the father and the child and how the child perceives his father. As Lord Justice Ward said in Re S (Parental Responsibility)  2 FLR 648 CA: It seems to me important, therefore, wherever possible, to ensure that the law confers upon a committed father that stamp of approval, lest the child grow up with some belief that he is in some way disqualified from fulfilling his role and that the reason for the disqualification is something inherent which will be inherited by the child, making her struggle to find her own identity all the more fraught.;
the father with Parental Responsibility will expect to be involved with the care of the child even if he is not caring for the child on a day-to-day basis and would normally be given access to school reports and medical records for that purpose;
even if the father is not involved with the routine care of a child, there may come a time where the father is required to be in that position and having Parental Responsibility would be important in those circumstances to make (or help to make by agreement) day-to-day decisions in relation to the child's welfare;
one parent with Parental Responsibility acting alone cannot cause the child to be known by a different surname without the consent of every person with Parental Responsibility for that child, and when one parent or person with Parental Responsibility asks a school, doctor or similar responsible person or body to start using a new surname that person or body should establish to its own satisfaction who has Parental Responsibility for that child. Once so satisfied it should only use or record the new surname if satisfied that all persons who have Parental Responsibility consent to the change or there is a court order authorising or giving leave for the change, see: Re C (Minors) (Change of Surname) sub nom Re PC (Change of Surname) (1996) Fam Div (Holman J) 19/6/96;
in accordance with The Children Act 1989 s.13(1)(a), no person may cause a child to be known by a new surname without the written consent of all those with Parental Responsibility or the leave of the court.
Points to Note
It is important to note a number of other points in relation to Parental Responsibility:
more than one person may have Parental Responsibility for the same child at the same time (Children Act 1989 s.2(5));
a person who has Parental Responsibility does not lose it just because someone else acquires it (Children Act 1989 s.2(6));
if more than one person has Parental Responsibility for a child, each of them may exercise that Parental Responsibility alone or with each other (Children Act 1989 s.2(7));
if a person has Parental Responsibility for a child, that person cannot surrender or transfer any of that responsibility to another person, but, someone can arrange for another person to exercise Parental Responsibility on their behalf (Children Act 1989 s.2(9));
someone with Parental Responsibility cannot avoid liability for failing to meet that responsibility by arranging for someone else to exercise it on his or her behalf (Children Act 1989 s.2(11)).
whether someone has Parental Responsibility for a child does not affect any obligations they may have in relation to the child (like a duty to pay Child Support) or affect any rights the person may have in relation to the child's property if the child were to die (Children Act 1989 s.3(4)).