A Google Groups thread reports issues with using the Google AdWords Verify Code option. The verify code tool seems to have been removed.

Why? AdWordsPro.Steph said it was removed because it came with the PPA (Pay Per Action) options. Google dropped the PPA program back in July and slowly phased out the Verify Code tool in September. Steph said:

Hopefully this helps some advertisers that are looking for the tool.

Forum discussion at Google Groups.