At the present time, there is only one independent PDR certification that is recognized by the NAPDRT:

Vale Training Solutions

This certification process is administered by the Vale Training Solutions.
Vale National has been instructing, training and certifying both Insurance personnel as well as auto body in a variety of programs in the automotive field for the last 57 years.
Vale National has created the only third party unbiased PDR Certification process.
Using industry standard damage assessment criteria and a state-of-the-art
surface measurement system, repairs to panels with varying degrees
of damage provide objective verification of the skill level of each applicant.
Repaired metal surface, variation tolerances, finish and appearance
are assessed.
The NAPDRT does not recognize self certified practices as a valid certification process
For more information on becoming a Vale National Certified PDR Technician