Illinois Petition for Letters of Administration is a formal legal document filed with the probate court in order to appoint a personal representative in the event that the deceased did not have a will. This document is filed when an individual has died and there is no will or other estate plan in place. The Petition will outline the relationship between the petitioner and the deceased, list the names of the decedent's heirs and other interested parties, and present evidence of the decedent's death. Depending on the circumstances, there are several types of Illinois Petitions for Letters of Administration. These include general letters of administration, letters of special administration, and letters of independent administration. In all cases, the Petition should be accompanied by the original death certificate, and the court may request additional information or documents.