At this time, there is no universal industry-wide accepted certification; however, several organizations offer certifications.
I have listed just a few below.
Preparing for the certifications will increase your knowledge of tools and issues.
Obtaining the certifications proves your commitment to potential clients and employers.
California State University, Northridge and CSUN
Online course, The Assistive Technology Certificate Program (ATACP) offers tools and techniques to achieve accessibility.
DHS Trusted Tester Program (TTP)
Is an extensive course on application and website accessibility testing with a certification in demand by United States government agencies and commercial companies.
International Association of Accessibility Professionals (IAAP)
Provides a certification test for the Certified Professional in Accessibility Core Competencies (CPACC). The IAAP community recommends taking the DEQUE web accessibility courses to prepare for the test.
Media Access Australia
The University of South Australia offers a university-accredited web accessibility certificate called, Professional Certificate in Web Accessibility (PCWA). It is a six-week on-line course.