86 Ill. Adm. Code 130.820
Preservation of Books During Pendency of Assessment Proceedings
Section 130
Section 130.820Â Preservation
of Books During Pendency of Assessment Proceedings
If a
notice of tax liability
has been issued, and if the questions raised
by such notice
have not been completely disposed of,
books and records reflecting receipts received during the period covered by
such
notice of tax liability
must be preserved
until the termination of all proceedings before the Department
or any other legal proceeding is concluded
.