Also referred to as Regulation Z. Part of the Consumer Credit Protection Act. Federal legislation designed to protect borrowers by requiring lenders to furnish information regarding the cost of the loan. The law requires interest to be expressed as the annual percentage rate (APR) to the nearest 1/8 of one percent. The APR must include charges such as loan fees, discount points, servicing fees, etc., as well as interest. The law applies to 1 to 4 family residential property only. Also applies to other consumer loans.