I found the WorldCat Identities API useful for an institution name disambiguation project that I worked on a few years ago, though my goal wasn't to confirm whether names mapped to LCNAF. The API response includes a LCCN, and you can set it to fuzzy or exact matching, but you would need to write a script to pass each term in and process the results:
I also can't speak to whether all LC Name Authorities are represented, so there may be a chance of some false negatives.
OCLC has another API, but not sure if it covers corporate names:
I suspect there are others on the list that know more about the inner workings of these APIs if this might be an option for you... :)
From: Code for Libraries [mailto:[log in to unmask]] On Behalf Of Ethan Gruber
Sent: Friday, September 26, 2014 3:54 PM
To: [log in to unmask]
Subject: Re: [CODE4LIB] Reconciling corporate names?
I would check with the developers of SNAC ( http://socialarchive.iath.virginia.edu/), as they've spent a lot of time developing named entity recognition scripts for personal and corporate names. They might have something you can reuse.
On Fri, Sep 26, 2014 at 3:47 PM, Galligan, Patrick <[log in to unmask]>
> I'm looking to reconcile about 40,000 corporate names against LCNAF to
> see whether they are authorized strings or not, but I'm drawing a
> blank about how to get it done.
> I've used http://freeyourmetadata.org/ for reconciling subject
> headings before, but I can't get it to work for LCNAF. Has anyone had
> any experience in a project like this? I'd love to hear some ideas for
> automatically dealing with a large data set like this that we did not
> create and do not know how the names were created.
> -Patrick Galligan