Illinois Code § 22

§ 22.

When subsequent purchases are made, if the seller has retained or taken a security interest in any of the goods purchased under any one of the contracts included in the consolidation he (1) shall apply the entire amount of all payments made before the subsequent purchases to the previous purchases; (2) shall allocate each payment on the consolidated contract after the subsequent purchases to all of the various purchases in the same ratio as the original cash sale prices of the various purchases bear to the total of all; (3) may, at his option, where the amount of each installment payment is increased in connection with a subsequent purchase, allocate the subsequent payments by applying an amount equal to the original periodic payment to the previous purchase and the balance to the subsequent purchase. However, he must allocate the amount of any down payment on the subsequent purchase in its entirety to the subsequent purchase. This Section does not apply to subsequent purchases involving equipment or other goods attached or affixed to goods previously purchased and not fully paid for, or to services in connection therewith rendered by the seller at the buyer's request. (Source: Laws 1967, p. 2149.)