765 ILCS 905/2
Every mortgagee of real property, his or her assignee of record, or other legal representative, having received full satisfaction and payment of all such sum or sums of money as are really due to him or her from the mortgagor, and every trustee, or his or her successor in trust, in a deed of trust in the nature of a mortgage, the notes, bonds or other indebtedness secured thereby having been fully paid before September 7, 1973, shall, at the request of the mortgagor, or grantor in a deed of trust in the nature of a mortgage, his or her heirs, legal representatives or assigns, or a person authorized by such mortgagor, grantor, heir, legal representative, or assign, in case such mortgage or trust deed has been recorded or registered, make, execute and deliver to the mortgagor or grantor in a deed of trust in the nature of a mortgage, his or her heirs, legal representatives or assigns, or a person authorized by the mortgagor, grantor, heir, legal representative, or assign, an instrument in writing executed in conformity with the provisions of this Section releasing such mortgage or deed of trust in the nature of a mortgage, which release shall be entitled to be recorded or registered and the recorder or registrar upon receipt of such a release and the payment of the recording fee therefor shall record or register the same.
Mortgages of real property and deeds of trust in the nature of a mortgage shall be released of record only in the manner provided herein or as provided in the Mortgage Certificate of Release Act; however, nothing contained in this Act shall in any manner affect the validity of any release of a mortgage or deed of trust made prior to January 1, 1952 on the margin of the record.
Except in the case of a mortgage that is required to be released under the Mortgage Certificate of Release Act, every mortgagee of real property, his or her assignee of record, or other legal representative, having received full satisfaction and payment of all such sum or sums of money as are really due to him or her from the mortgagor, and every trustee, or his or her successor in trust, in a deed of trust in the nature of a mortgage, the notes, bonds or other indebtedness secured thereby having been fully paid after September 7, 1973, shall make, execute and deliver to the mortgagor or grantor in a deed of trust in the nature of a mortgage, his or her heirs, legal representatives or assigns, or person authorized by such mortgagor, grantor, heir, legal representative, or assign, an instrument in writing releasing such mortgage or deed of trust in the nature of a mortgage or shall deliver that release to the recorder or registrar for recording or registering. If the release is delivered to the mortgagor or grantor, it must have imprinted on its face in bold letters at least 1/4 inch in height the following: "FOR THE PROTECTION OF THE OWNER, THIS RELEASE SHALL BE FILED WITH THE RECORDER OR THE REGISTRAR OF TITLES IN WHOSE OFFICE THE MORTGAGE OR DEED OF TRUST WAS FILED". The recorder, or registrar, upon receipt of such a release and the payment of the recording or registration fee, shall record or register the release. A certificate of release issued and recorded by a title insurance company or its duly appointed agent pursuant to the Mortgage Certificate of Release Act shall satisfy the requirements of this Section 2.
765 ILCS 905/2