The full form of APACS is Association of Payment and Clearing Services

The Association for Payment Clearing Services is a non-statutory association of major banks and building societies. It provides the forum for banks and building societies to discuss non-competitive issues relating to money transmission. One of APACS’ principal tasks is to manage the major UK payment clearing systems. This is currently carried out by three operational clearing companies: Cheque and Credit Clearing Company which oversees the paper clearing. CHAPS Clearing Company which provides electronic same-day clearings in sterling and euro.BACS which operates the bulk electronic clearing. A link from the front page of this website, gives access to information about CHAPS and its members.