Read the last paragraph on page 3 of that publication:
"May I receive a refund if my property tax credit
exceeds the income tax I owe?
If your property tax credit exceeds the income tax you owe, you may
not receive a refund for that amount, and you may not carry unused
credit to other years. Your property tax credit may only reduce the
income tax you owe to zero."
My income tax owed was already zero because I only have retirement- Pension, SS and 401k and they are not taxed in IL.
