750 ILCS 75/40
A civil union may be certified: by a judge of a court of record; by a retired judge of a court of record, unless the retired judge was removed from office by the Judicial Inquiry Board, except that a retired judge shall not receive any compensation from the State, a county, or any unit of local government in return for the solemnization of a civil union and there shall be no effect upon any pension benefits conferred by the Judges Retirement System of Illinois; by a judge of the Court of Claims; by a county clerk in counties having 2,000,000 or more inhabitants; by a public official whose powers include solemnization of marriages; or in accordance with the prescriptions of any religious denomination, Indian Nation or Tribe or Native Group, provided that when such prescriptions require an officiant, the officiant be in good standing with his or her religious denomination, Indian Nation or Tribe or Native Group. The person performing a civil union shall complete the certificate and forward it to the county clerk within 10 days after a civil union.
750 ILCS 75/40