While banks can send and receive their check image files through the Federal Reserve, now they can quickly and inexpensively add clearing options through their bankers' bank, other correspondent or processor. Private-sector paper check exchange is governed by the Uniform Commercial Code (UCC), clearinghouse rules, the Expedited Funds Availability Act, Regulation CC (Availability of Funds and Collection of Checks) and large volumes of case law. The Electronic Check Clearing House Organization, or ECCHO, was created in 1990 and is a national clearinghouse and the rules provider for check image exchange. The ECCHO Rules for check image exchange fill the legal gaps by using UCC provisions granting clearinghouses the ability to modify certain aspects of the UCC to create and maintain rules binding all transaction parties. The rules, offered exclusively to ECCHO members, are designed to be vendor and solution independent. ECCHO's membership has grown rapidly since the passage of the Check 21 Act.