In North Carolina, the only thing necessary for a legal separation is for one spouse to move out of the home without the intention of returning and resuming the marital relationship. No legal documents are necessary (although separation agreements are often highly recommended).
Many people ask if they will be guilty of abandonment if they choose to move out of the marital home in order to effectuate a legal separation. As long as you felt that you were justified in leaving, you will most likely not be held liable for abandonment. For instance, if you have been emotionally, mentally or physically abused by your spouse, you would have grounds to leave the home. Similarly, if your spouse has made your life burdensome and intolerable you would be justified in leaving to reduce the negative impact your spouse has had upon your life. If you recently found out your spouse has cheated on you during the marriage, your leaving would be justified.
If you do choose to move out of the marital home and establish your own residence, keep in mind there are laws that prohibit your return without the permission of the spouse who remains in the home. Domestic criminal trespass is a criminal charge and can apply even if your name remains on the deed to the house at the time of your separation. This law can have significant effects on the issue of child custody and visitation as well.
There are several factors that can go into the analysis of whether a spouse is guilty of abandonment, and the effects of legal separation; those should be fully discussed with an attorney so that you will understand your rights and obligations pursuant to North Carolina law.