I'm doing some patent processing and was wondering if there's a master database somewhere (Bloomberg, D&B?) which uniquely identifies companies that I could map patent owners/assignees into. The company names in the filings aren't always consistent, or may change name while keeping the same legal entity. I'd prefer not to generate my own name/alias lookup if something already exists.
I'd prefer something from public data sources, as it seems D&B has private identifiers. I'm looking into EDGAR, but I'm not sure that's comprehensive enough since it's based on voluntary SEC filings.