(815 ILCS 405/2.15) (from Ch. 121 1/2, par. 502.15)

Sec. 2.15. "Annual percentage rate" means the nominal annual percentage rate of finance charge determined in accordance with the actuarial method of computation with an accuracy at least to the nearest 1/4 of 1%; or at the option of the seller, by application of the United States rule so that it may be disclosed with an accuracy at least to the nearest 1/4 of 1%.

(Source: P.A. 76-1780.)