The Consumer Electronic Clearing System (CECS) or Clearing Stream 3 (CS3) was established in December 2000 following a favourable determination issued by the Australian Competition and Consumer Commission (ACCC) in August 2000.

In CECS the management of clearing primarily involves setting minimum interchange standards to protect and enhance the security, integrity and efficiency of exchanges of consumer electronic payment messages. As initially established, CECS covers ATM interchanges and EFTPOS only. Providers of credit cards (Visa and MasterCard) have set their own rules for participation in their respective schemes, and for clearing where it arises. Therefore these payment instruments have not been included in the interchanges covered by the CECS rules. Other types of interchange activities can be covered later by determination of APCA directors on the recommendation of the CECS management committee.

The CECS manual covers a number of standards for the operation of the national ATM and EFTPOS network.

Members of CECS may settle directly or indirectly but there are no separate categories of membership. Eligibility for membership is, however, based on the type of interchange activity which the member engages in. Members need to be engaging in interchange activities in either the capacity of an acquirer or an issuer of cards, or represent one or more acquirers or issuers and effect settlement directly. For membership purposes, an acquirer includes a "Merchant Principal" which includes retailers which directly switch transactions to card issuers.