Although usability is now considered fundamental factor for the success of software or Internet applications, a national and international body that can certify corporations and their employees to document their competence in the application of usability measures and process in their respective business segments, still does not exist.
Thanks to the International Board for Usability and User Experience Qualification (IBUQ) this status has now been changed. Businesses now have access of a significant quality seal that allows them to document their expertise in the discipline of Usability through certification.  

The IBUQ Association improves and promotes the user friendliness and utilization conveniences of interactive human-machine interfaces. Based on national and international statutes, standards and requirements, the Association develops up-to-date usability standards and conducts certification services for businesses and/or their employees.

Further info can be found here