Deciding which parent the children will live with
The law in respect of where a child in England & Wales lives is governed by the Children Act 1989. Whilst the phrase is still used today, the 'custody' of a child has not been used in the courts since October 1991.
Until April 2014 the courts applied the terminology 'residence' for the parent with care of the child and contact for the non-resident parent. Since April 2014 the courts have used the phrase 'child arrangements order' to cover these issues. If you are seeking for your child to live with you it is a child arrangements - living with order and if you wish to see your child it is a child arrangements - spending time with order.
If such an order is made either for one person or on a shared basis then that person can take the child out of the jurisdiction of England & Wales for up to a month without the need to obtain the consent of the other parent unless a separate order is in existence stopping the same.
Most child arrangements orders remain in place until a child is 16 but in exceptional circumstances this extends to when a child is 18. Until 2001 the vast majority of private children cases led to a child living with one parent for the majority of time. Since then there has been a growing but still minority of cases where the child spends time with both parents by way of a shared child arrangements order.
The courts in England & Wales operate a no order policy i.e. they will only make an order if it is in the child's best interests to do so.