How To Look Up A TIN Number Securely
The IRS makes it possible for business entities to look up federal taxpayer identification numbers in order to verify that the company name and TIN number match up with data that may be on file with banks, financial institutions, or other parties that may need the numbers in order to make payments or keep records.
Check Your File Cabinet
You may already have a TIN number listed on form CP-575, which also tells you how the IRS sees the name and number of your company. One big problem for companies that take payments from credit card processors or PayPal is that they may see withholding if they don't have an exact match in the database, and often this is due to transcription errors on the financial entity's behalf. In some cases this could be the result of an ampersand being used in place of the word "and" or vice versa, so "Smith & Sons, LLC" in the IRS file would not match "Smith and Sons, LLC" in the processor's database. Compounding the issue is older databases that would automatically replace words with symbols.
Getting Another Company's Federal Tax ID For Record Keeping
Typically, if you are a vendor,
buyer, or seller then you may need to request or give a Taxpayer ID number. This is done on form W9, which gets filled out and given to the requeting party, not the IRS. For example, if you do B2B sales and a company is sending a 1099 form to the IRS, it will need your TIN as well as the legal business entity name. Most receptionists and accountants have a pre-filled W9 that they copy or fax to be sent over to the other party. This is the IRS Page which will get you to the PDF of the form and supporting documentation.
If a company has already sent you a W-2 form or 1099, then you may have their TIN already. Look for fields that contain taxpayer identification numbers, but be careful that you aren't using state or local EINs which may be different.
Note: There are also online services that catalog EIN numbers and verify numbers. These searches are often done to comply with "know your customer" (KYC) laws and for verification on 1099, customs, and vendor verifications. It is important to remember that you may be able to use this to verify an existing number in some cases, but not just get a vast collection of TINs.