In order to guarantee quality and to ensure compliance with the IO-Link Standards, IO-Link provides support by competence center and test laboratories.

IOL-Competence Centers (IOL-CCs) are centers of technical expertise. They offer technical support to anyone who needs it and they play an essential role in supporting first-time developers of IO-Link devices and systems.
Here's a list of the competence center.

IO-Link Test Laboratories (IOL-TL) are test centers authorized
by the IO-Link community to execute tests for Manufacturer Declarations
of IO-Link devices and masters.
Here's a list of the test labs.