You may figure a credit for the Illinois property taxes you paid in 2017 on your principal residence (not a vacation home or rental property) for the time you owned and lived at the property during 2017, if that residence was in Illinois. Nonresidents of Illinois may not take this credit.
You may not figure a credit for mobile home privilege tax, penalties, or fees included in your property tax bill, or the portion of the property that is deductible as a business expense.
Line 4a - Enter the total amount of Illinois Property Tax paid during the tax year for the real estate that includes your principal residence.
Line 4b - Enter the name of the county and the property number, sometimes called "property index number," "parcel number," or "permanent number" for the property listed on Line 4a.
Note. You must enter your property number exactly as it appears on your property tax bill or assessment notice. Your property number is found near the top of your property tax bill or assessment notice. If your property taxes are paid through your mortgage, you may contact your lender for your property number.
You may also get this number from your county assessor’s office. A list of counties, with contact information, is under the “Individuals” section of our website
Lines 4c and 4d - Enter the name of the county and the property number for any lots that adjoin your principal residence, are used for residential purposes, and you included when calculating the total amount of property tax paid on Line 4a.
To enter or review your property tax credit information: