A Taxpayer Identification Number (TIN) is a nine digit number that the Internal Revenue Services uses to track tax records of businesses. The TIN, also called an Employer Identification Number (EIN), is assigned to many different types of businesses, including corporations, private companies, churches and non-profit organisations. There are several ways to try to locate an EIN -- which method you use depends on whether the company is for-profit or non-profit.
Call the company or visit the company’s website. The TIN may be listed on the website (try the “About” page) or there may be documents on the site that contain the TIN. For example, invoices usually have TIN numbers printed on them.
Find a publicly traded company's SEC filings at the Securities and Exchange Commission’s Edgar website. The TIN or EIN will be listed on the first page of any filings.
Obtain a company's IRS form 990, if they are a non-profit organisation. The TIN will be listed on the 990. You can obtain a copy of a company's 990 directly from the IRS.
Locate the TIN using an online database. For example, The Foundation Center keeps a record of non-profit 990s for the last three to five years. You may also be able to find a for-profit company's information at KnowX.com or FEINSearch.com
Unlike publicly traded entities, private companies do not have disclose business information like the TIN. Obtaining this information may prove to be a challenge. If you have been unsuccessful in obtaining the TIN, try calling the accounting department for the information.