The contents of this appendix were taken from the ( http://www.achrulesonline.org)

The ACH Network supports a variety of payment applications. An Originator initiating entries into the system will code the entries in such a manner as to indicate the type of payment, such as a debit or credit, and whether an entry is consumer or corporate in nature (that is, the funds transfer affects either a consumer account or a corporate account at the RDFI). Each ACH application is identified and recognized by a specific three-digit code, known as a Standard Entry Class (SEC) code, which appears in the ACH record format. The SEC code identifies the specific computer record format that will be used to carry the payment and payment-related information relevant to the application.

This appendix presents a list of SEC codes and the different products each code supports.