The process for evicting an adult child is similar to that of evicting a tenant for nonpayment of rent. The process begins with filing a "Notice to Quit" and moves toward court proceedings if the person who receives the notice refuses to leave, according to Illinois Legal Aid Online.
For a child under the age of 18, eviction is not possible, as parents have legal duties to minor children. However, those duties end once the child turns 18. Some parents sign lease agreements with adult children and require monthly rent payments. Even without a lease agreement, eviction proceedings can still take place, notes Illinois Legal Aid Online.
The first step in the eviction process includes a formal "Notice to Quit." This consists of a letter asking for immediate possession of the property in question, states Illinois Legal Aid Online. If the child does not leave, the next step is filing an eviction proceeding in court. The child receives a copy of the complaint and a summons to appear in court. He can ask for a trial in which he has to prove a right to keep living in the house or prove a way in which the parent made a procedural error. The judge issues an eviction order if the child fails to do either of those, and the parent can then ask the sheriff to remove the child and his belongings.