Cut-rate SEO firms like to state that they are “certified by Google” or a “Google Partner” even when this doesn’t apply to SEO.

If an agency is “certified,” that means that they have completed Google training for Adwords and/or Google Analytics.  If they state that they are a “Google Partner,” they are a partner for paid Google advertising only.  There is no such thing as a Google SEO partner, nor is there a Google SEO certification program.