The seminal case in this area of law is Dawson v Wearmouth in 1999.
The following principles arise from that judgment (taken from the legal publication Butterworths Family Law Service:
(1) If the parents are married, they both have the power and duty to register their child's names, and each has an equal voice in the name to be chosen at the outset.
(2) If they are not married, the mother has the sole duty and power to do so. The initial choice is hers, and she can change the surname; but the father has the right to challenge both choice and change under the Children Act 1989, s 8.
(3) After registration of the child's names, the grant of a child arrangements order (formerly a residence order) obliges any person wishing to change the surname to obtain the leave of the court or the written consent of all those who have parental responsibility.
(4) In the absence of a child arrangements order (formerly a residence order), the person wishing to change the surname from the registered name must obtain the relevant written consent or the leave of the court by making an application for a specific issue order.
(5) In any application the welfare of the child is paramount.
(6) Among the factors to which the court should have regard is the registered surname of the child and the reasons for the registration, for instance recognition of the biological link with the child's father. Registration is always a relevant and important consideration, but is not in itself decisive.
(7) Relevant considerations should include factors which could arise in the future as well as the present.
(8) Reasons given for changing or seeking to change a child's name based on the fact that his name is not the same as the parent making the application do not generally carry much weight.
(9) The reasons for an earlier unilateral decision to change a child's name may be relevant.
(10) Any change of circumstances of the child since the original registration may be relevant.
(11) In the case of a child whose parents are married to each other, the fact of the marriage is important, and there will have to be strong reasons to change the name from the father's surname if the child has been so registered.
(12) Where the child's parents are not married to each other, the mother has control over registration. Consequently, on an application to change the surname of the child, the degree of commitment of the father to the child, the quality of contact, if it has occurred, between them, the existence or absence of parental responsibility are all relevant factors to take into account