(815 ILCS 205/4) (from Ch. 17, par. 6404)
    Sec. 4. General interest rate.
    (1) Except as otherwise provided in Section 4.05, in all written contracts it shall be lawful for the parties to stipulate or agree that 9% per annum, or any less sum of interest, shall be taken and paid upon every $100 of money loaned or in any manner due and owing from any person to any other person or corporation in this state, and after that rate for a greater or less sum, or for a longer or shorter time, except as herein provided.
    The maximum rate of interest that may lawfully be contracted for is determined by the law applicable thereto at the time the contract is made. Any provision in any contract, whether made before or after July 1, 1969, which provides for or purports to authorize, contingent upon a change in the Illinois law after the contract is made, any rate of interest greater than the maximum lawful rate at the time the contract is made, is void.
    It is lawful for a state bank or a branch of an out-of-state bank, as those terms are defined in Section 2 of the Illinois Banking Act, to receive or to contract to receive and collect interest and charges at any rate or rates agreed upon by the bank or branch and the borrower. It is lawful for a savings bank chartered under the Savings Bank Act or a savings association chartered under the Illinois Savings and Loan Act of 1985 to receive or contract to receive and collect interest and charges at any rate agreed upon by the savings bank or savings association and the borrower.
    It is lawful to receive or to contract to receive and collect interest and charges as authorized by this Act and as authorized by the Consumer Installment Loan Act and by the "Consumer Finance Act", approved July 10, 1935, as now or hereafter amended, or by the Payday Loan Reform Act. It is lawful to charge, contract for, and receive any rate or amount of interest or compensation with respect to the following transactions:
        (a) Any loan made to a corporation;
        (b) Advances of money, repayable on demand, to an
    
amount not less than $5,000, which are made upon warehouse receipts, bills of lading, certificates of stock, certificates of deposit, bills of exchange, bonds or other negotiable instruments pledged as collateral security for such repayment, if evidenced by a writing;
        (c) Any credit transaction between a merchandise
    
wholesaler and retailer; any business loan to a business association or copartnership or to a person owning and operating a business as sole proprietor or to any persons owning and operating a business as joint venturers, joint tenants or tenants in common, or to any limited partnership, or to any trustee owning and operating a business or whose beneficiaries own and operate a business, except that any loan which is secured (1) by an assignment of an individual obligor's salary, wages, commissions or other compensation for services, or (2) by his household furniture or other goods used for his personal, family or household purposes shall be deemed not to be a loan within the meaning of this subsection; and provided further that a loan which otherwise qualifies as a business loan within the meaning of this subsection shall not be deemed as not so qualifying because of the inclusion, with other security consisting of business assets of any such obligor, of real estate occupied by an individual obligor solely as his residence. The term "business" shall be deemed to mean a commercial, agricultural or industrial enterprise which is carried on for the purpose of investment or profit, but shall not be deemed to mean the ownership or maintenance of real estate occupied by an individual obligor solely as his residence;
        (d) Any loan made in accordance with the provisions
    
of Subchapter I of Chapter 13 of Title 12 of the United States Code, which is designated as "Housing Renovation and Modernization";
        (e) Any mortgage loan insured or upon which a
    
commitment to insure has been issued under the provisions of the National Housing Act, Chapter 13 of Title 12 of the United States Code;
        (f) Any mortgage loan guaranteed or upon which a
    
commitment to guaranty has been issued under the provisions of the Veterans' Benefits Act, Subchapter II of Chapter 37 of Title 38 of the United States Code;
        (g) Interest charged by a broker or dealer registered
    
under the Securities Exchange Act of 1934, as amended, or registered under the Illinois Securities Law of 1953, approved July 13, 1953, as now or hereafter amended, on a debit balance in an account for a customer if such debit balance is payable at will without penalty and is secured by securities as defined in Uniform Commercial Code-Investment Securities;
        (h) Any loan made by a participating bank as part of
    
any loan guarantee program which provides for loans and for the refinancing of such loans to medical students, interns and residents and which are guaranteed by the American Medical Association Education and Research Foundation;
        (i) Any loan made, guaranteed, or insured in
    
accordance with the provisions of the Housing Act of 1949, Subchapter III of Chapter 8A of Title 42 of the United States Code and the Consolidated Farm and Rural Development Act, Subchapters I, II, and III of Chapter 50 of Title 7 of the United States Code;
        (j) Any loan by an employee pension benefit plan, as
    
defined in Section 3 (2) of the Employee Retirement Income Security Act of 1974 (29 U.S.C.A. Sec. 1002), to an individual participating in such plan, provided that such loan satisfies the prohibited transaction exemption requirements of Section 408 (b) (1) (29 U.S.C.A. Sec. 1108 (b) (1)) or Section 2003 (a) (26 U.S.C.A. Sec. 4975 (d) (1)) of the Employee Retirement Income Security Act of 1974;
        (k) Written contracts, agreements or bonds for deed
    
providing for installment purchase of real estate, including a manufactured home as defined in subdivision (53) of Section 9-102 of the Uniform Commercial Code that is real property as defined in the Conveyance and Encumbrance of Manufactured Homes as Real Property and Severance Act;
        (l) Loans secured by a mortgage on real estate,
    
including a manufactured home as defined in subdivision (53) of Section 9-102 of the Uniform Commercial Code that is real property as defined in the Conveyance and Encumbrance of Manufactured Homes as Real Property and Severance Act;
        (m) Loans made by a sole proprietorship, partnership,
    
or corporation to an employee or to a person who has been offered employment by such sole proprietorship, partnership, or corporation made for the sole purpose of transferring an employee or person who has been offered employment to another office maintained and operated by the same sole proprietorship, partnership, or corporation;
        (n) Loans to or for the benefit of students made by
    
an institution of higher education.
    (2) Except for loans described in subparagraph (a), (c), (d), (e), (f) or (i) of subsection (1) of this Section, and except to the extent permitted by the applicable statute for loans made pursuant to Section 4a or pursuant to the Consumer Installment Loan Act:
        (a) Whenever the rate of interest exceeds 8% per
    
annum on any written contract, agreement or bond for deed providing for the installment purchase of residential real estate, or on any loan secured by a mortgage on residential real estate, it shall be unlawful to provide for a prepayment penalty or other charge for prepayment.
        (b) No agreement, note or other instrument evidencing
    
a loan secured by a mortgage on residential real estate, or written contract, agreement or bond for deed providing for the installment purchase of residential real estate, may provide for any change in the contract rate of interest during the term thereof. However, if the Congress of the United States or any federal agency authorizes any class of lender to enter, within limitations, into mortgage contracts or written contracts, agreements or bonds for deed in which the rate of interest may be changed during the term of the contract, any person, firm, corporation or other entity not otherwise prohibited from entering into mortgage contracts or written contracts, agreements or bonds for deed in Illinois may enter into mortgage contracts or written contracts, agreements or bonds for deed in which the rate of interest may be changed during the term of the contract, within the same limitations.
    (3) In any contract or loan which is secured by a mortgage, deed of trust, or conveyance in the nature of a mortgage, on residential real estate, the interest which is computed, calculated, charged, or collected pursuant to such contract or loan, or pursuant to any regulation or rule promulgated pursuant to this Act, may not be computed, calculated, charged or collected for any period of time occurring after the date on which the total indebtedness, with the exception of late payment penalties, is paid in full.
    (4) For purposes of this Section, a prepayment shall mean the payment of the total indebtedness, with the exception of late payment penalties if incurred or charged, on any date before the date specified in the contract or loan agreement on which the total indebtedness shall be paid in full, or before the date on which all payments, if timely made, shall have been made. In the event of a prepayment of the indebtedness which is made on a date after the date on which interest on the indebtedness was last computed, calculated, charged, or collected but before the next date on which interest on the indebtedness was to be calculated, computed, charged, or collected, the lender may calculate, charge and collect interest on the indebtedness for the period which elapsed between the date on which the prepayment is made and the date on which interest on the indebtedness was last computed, calculated, charged or collected at a rate equal to 1/360 of the annual rate for each day which so elapsed, which rate shall be applied to the indebtedness outstanding as of the date of prepayment. The lender shall refund to the borrower any interest charged or collected which exceeds that which the lender may charge or collect pursuant to the preceding sentence. The provisions of this amendatory Act of 1985 shall apply only to contracts or loans entered into on or after the effective date of this amendatory Act, but shall not apply to contracts or loans entered into on or after that date that are subject to Section 4a of this Act, the Consumer Installment Loan Act, the Payday Loan Reform Act, or the Retail Installment Sales Act, or that provide for the refund of precomputed interest on prepayment in the manner provided by such Act.
    (5) For purposes of items (a) and (c) of subsection (1) of this Section, a rate or amount of interest may be lawfully computed when applying the ratio of the annual interest rate over a year based on 360 days. The provisions of this amendatory Act of the 96th General Assembly are declarative of existing law.
    (6) For purposes of this Section, "real estate" and "real property" include a manufactured home, as defined in subdivision (53) of Section 9-102 of the Uniform Commercial Code that is real property as defined in the Conveyance and Encumbrance of Manufactured Homes as Real Property and Severance Act.
(Source: P.A. 98-749, eff. 7-16-14.)