A tax ID lookup in the United States is not one search against one database. There is no public directory of employer identification numbers that anyone can query by company name, which is the first thing worth knowing before spending an afternoon looking for one. What exists instead is a set of places the number surfaces because a company had to disclose it, and knowing which of those applies to your company is the whole of the task.
Why there is no public EIN directory
The employer identification number is issued by the Internal Revenue Service, and the IRS does not publish a searchable index of which number belongs to which business. Federal tax information is protected, and the number is treated as part of it. That is why a search that expects to type a company name and get a number back comes up empty: the directory being searched for has never existed. Everything below is a route to the number through a filing the company itself made public, not through a central index.
Where the number is genuinely public
Three routes work often enough to be worth trying. A company that files with the Securities and Exchange Commission puts its number on the cover of its filings. A tax-exempt organisation has its number published, because exempt status is a public matter. And some state registers surface a state tax or registration number that is not the federal one but does the same identifying job for state purposes. Which of the three applies depends entirely on what kind of company you are looking at.
What a state register gives you instead
A state business register will not give you a federal employer identification number, but it gives you the things the number is usually being sought to establish: that the entity exists, that it is active, what its legal name and file number are, who its registered agent is, and when it was formed. For a contract, a bank onboarding or a supplier check, that record is often what was actually needed. Ask the company for the federal number directly if the record will not do.
Questions people ask about tax id lookup
Is there a free public EIN lookup by company name?
No. The IRS publishes no searchable index of employer identification numbers by name. The number surfaces only through filings a company or organisation made public.
What is the difference between a state tax ID and a federal EIN?
The federal EIN is issued by the IRS. A state tax or registration number is issued by a state agency and identifies the business for state purposes only. They are different numbers.
If I cannot find the number, what should I use?
The state register record: legal name, file number, status, registered agent and formation date. For most contract and onboarding checks that record answers the underlying question.