IL SB2604

Amends the Uniform Penalty and Interest Act to modify penalty rates for failure to file and failure to pay tax returns effective January 1, 2019.

Changes late payment penalties under subsection (b-20) from a tiered structure (2%, 10%, 20%) to penalties of 2%, 10%, and 15%, with the 15% penalty abated if taxpayer paid at least 95% of total tax liability before Department initiated audit or investigation.

Modifies Section 3-9 to clarify that penalties are imposed at rates in effect when tax liability became due, except as provided in subsection (b-20) of Section 3-3.

Applies changes retroactively only to penalties assessed on or after the effective date; penalties assessed prior to January 1, 2019 are unaffected by these amendments.