Payday loans in Chicago, IL as well as in any other city of Illinois state are LEGAL according to Ill. Comp. Stat. Ann. u00a7 122/1-11. $100 - $1,000 (but not more than 25% of gross monthly income) cash advance can be borrowed for 13-45 days. The average APR stated by the state law is 403%, which is $15.50 charged per $100 for 14 days.