Simply put, RespOrg is a contraction for Responsible Organization. But responsible for what? A RespOrg is responsible for controlling and maintaining toll-free numbers for businesses. A RespOrg is also an entity that has gone through a certification process to gain access to the Service Management System or SMS 800, the 800 number database. RespOrgs can check availability, reserve numbers for customers and make changes to a customer’s account. Therefore, if your business has a toll free number, you have a RespOrg too.
Information taken from http://www.whatisresporg.info/what-is-resporg/