Tax identification numbers, or TINs, are available through the public records of corporate fillings for publicly held corporations. The TINs of privately held companies are not available to the public, says the Houston Chronicle.
To find the TIN of a public corporation, it is possible to search the Securities and Exchange Commission's database; certain forms listed on that database contain a corporation's TIN. It is also possible to make a request for a nonprofit's TIN for the purposes of donation receipts. Nonprofit corporations must maintain public records and must comply with requests for their TINs. If an individual needs to issue a 1099 tax form to a private corporation, he needs to ask that corporation to provide its TIN.