Where a person interferes with another person's custody of a child or right to access, the interfering person may be subject to a claim of tortious interference with custody and can be held financially liable. This may occur where one parent takes the child and refuses to divulge the child's whereabouts. However, tortious interference may not be limited to cases where a child is concealed.

Courts in several states have recognized that a person who interferes with a parent's natural right to custody of a child may be held liable for interfering in the parent-child relationship. The parent, whose rights were violated, may sue to recover compensatory damages, punitive damages, and attorney fees. Persons who have been held liable under such suits include parents, grandparents, third parties, and even attorneys, where the attorneys have failed to provide a current address of the child, as required.

In order to establish a claim of tortious interference, the interference may not be minor in nature. The failure to return a child on time after a period of visitation would not support such a claim, nor would the fact that a stepparent spoke in a hostile manner to a parent during a change of custody after a period of visitation. However, sending children off to Egypt, with no intention of ever returning them to the United States, where the father, who had lawful custody, lived, did support a claim of tortious interference. Grandparents, who did not themselves conceal a child from the parent who had custody, but who assisted the noncustodial parent by giving her financial aid and refusing to divulge the child or parent's whereabouts, were held liable.

The line as to what constitutes tortious interference and what does not is not very clear. Where a parent acts in such a manner that the child chooses to live with that parent, there is no tortious interference. On the other hand, where a mother lures a child into visiting her, with airline tickets and credit cards, knowing that the father, who has custody, did not consent, and induces the child not to return to the father, the court may find tortious interference. To be successful in proving tortious interference, the person suing must establish the use of fraud or deceit. To obtain damages, the parent does not have to prove loss of services; loss of companionship is sufficient.