35 ILCS 200/9-25

In counties under township organization, the township assessors and multi-township assessors shall allow the supervisor of assessments to make a duplicate copy of any or all records compiled and maintained by the township assessor and multi-township assessor. The supervisor of assessments shall make and maintain a complete set of property record cards. The township or multi-township assessor shall supply the supervisor of assessments with a copy of all new property record cards as they are added to the tax rolls.