Additional information.  I noticed that Missouri is phasing out the Federal Tax Deduction.  As a result, the taxes have increased in Missouri.  One possible explanation for the issue that I am observing on the Illinois Schedule CR could relate to this change in Missouri.  For example, the lower amount that is populated on the Illinois Schedule CR seems to correlate to the amount of taxes that "would have been calculated" had this Federal Tax Deduction change had not occurred.  It seems as if the Illinois Schedule CR form is not simply pulling information from a specific box on the Missouri form but rather doing some calculation of Missouri taxes based on the pre-2019 rules related to the Federal Tax Deduction on the Missouri Tax form.

According to the instructions, the credit in line 51 is calculated like this:  MO1040, Line 31 Minus Lines 29 (You/Spouse), 37, and 38. Do you have any entries in those lines?

Publication 111

 

How do I figure the amount of other states’ taxes to enter in Step 6 for tax years 2009 and after? Follow the Schedule CR Instructions. If you need further guidance, see the “Comparison Formulas for Schedule CR” found on our website for a list of formulas that identify the tax forms, line numbers, additions, and subtractions that you must use to compute the other states’ tax.