If you and your partner are married, you can separate by an informal arrangement. You will need to inform some or all of the people listed under the article Who to inform when your marriage ends. You may have a legal responsibility to tell:
If you and your partner agree, you can make arrangements about children, money, housing and other property without going to court. However, any informal arrangement made when you separate may affect future decisions if you do ever go to court.
A court may change an arrangement made by a couple that it considers to be unreasonable or, in the case of a child, if it’s not in the child’s best interests.