The Google Advertising Professional program which launched in 2004 had one major flaw. They were assigned to companies and the scores and professional status could not be transferred with the individual who took the test, to the new company he or she went to.

I am happy to say, that is no longer the case. A new program site for this certification, allows you to migrate your accounts from your old company to a new company. To access this feature, go to adwords.google.com/professionals/migrate. The site reads:

This feature is welcomed by many AdWords professionals.

Forum discussion at WebmasterWorld.