Illinois Statutes § 5/5-21 Mailed notice of registration-Procedure for correction or cancellation

To each person who registers at the office of the county, city, village, incorporated town or town clerk, or any place designated by the Board of County Commissioners under section 5-17 of article 5 and within five days thereafter, the election authority [County Clerk] shall send by mail , and electronic mail if the registrant has provided the election authority with an e-mail address, a notice setting forth the elector's name and address as it appears on the registration record card, and shall request him in case of any error to present the notice on or before the seventh day next ensuing at the office of the election authority [County Clerk] in order to secure the correction of the error. Such notice shall contain on the outside a request for the postmaster to return it within five days if it cannot be delivered to the addressee at the address given thereon. Upon the return by the post office of such notice which it has been unable to deliver at the given address because the addressee cannot be found there, a notice shall be at once sent through the United States mail to such person at the address appearing upon his registration record card requiring him to appear before the election authority [County Clerk] , within five days, to answer questions touching his right to register. If the person notified fails to appear at the election authority's [County Clerk's] office within five days as directed or if he appears and fails to prove his right to register, the election authority [County Clerk] shall cancel his registration.