Getting a tax ID number is free and, depending on the type you need, can take anywhere from a few minutes to several weeks. The term “tax ID number” covers a few different things: an Employer Identification Number (EIN) for a business, an Individual Taxpayer Identification Number (ITIN) for someone who needs to file taxes but isn’t eligible for a Social Security number, or a state tax ID for collecting sales tax or paying state payroll taxes. Here’s how to get each one.
Which Tax ID Number Do You Need?
Before you apply for anything, make sure you’re going after the right number. Most people searching for a tax ID number need one of three things:
- EIN (Employer Identification Number): A nine-digit number the IRS assigns to businesses. You need one if you have employees, operate as a corporation or partnership, file certain tax returns, or opened a business bank account. Even single-member LLCs often need an EIN.
- ITIN (Individual Taxpayer Identification Number): A nine-digit number for individuals who have a U.S. tax filing obligation but aren’t eligible for a Social Security number. This includes certain nonresident aliens, their spouses, and dependents.
- State tax ID: A separate number issued by your state’s tax agency, typically required if you collect sales tax or withhold state income tax from employees’ paychecks.
If you’re a U.S. citizen or permanent resident, your Social Security number already serves as your individual tax ID. You don’t need to apply for anything additional for personal tax filing.
How to Get an EIN
The IRS issues EINs at no cost, and the fastest way to get one is through the online application on IRS.gov. The process takes about 10 to 15 minutes, and you receive your EIN immediately at the end of the session. You never have to pay a fee for an EIN. If a website is asking you to pay, you’re not on the IRS site.
Online Application
The IRS online EIN application is available during limited hours (generally weekdays). To use it, the person applying must have a valid Social Security number or ITIN and a U.S. address. You’ll answer a series of questions about your business type, the reason you need an EIN, and the responsible party (the individual the IRS considers the primary contact). At the end, your EIN appears on screen, and you can download a confirmation notice right away.
Other Ways to Apply
If you can’t use the online tool, you have alternatives. You can fax Form SS-4 to the IRS and typically receive your EIN within four business days. You can also mail the same form, though that route takes four to six weeks. International applicants who don’t have a U.S. address can call the IRS directly to apply by phone.
Each business entity gets one EIN. If you’re starting multiple businesses as separate legal entities, each one needs its own number. A sole proprietorship without employees can often use the owner’s Social Security number instead, but getting an EIN is still a good idea to keep your personal number off invoices and business documents.
How to Get an ITIN
An ITIN is for individuals, not businesses, and the application process is more involved than an EIN. You apply using Form W-7, which you typically submit alongside your federal tax return. The IRS won’t issue an ITIN unless you have a tax filing requirement or qualify for a specific exception (like receiving certain types of income or being claimed as a dependent).
Documents You’ll Need
You must prove both your identity and your foreign status. A valid passport is the simplest option because it’s the only document that satisfies both requirements on its own. If you don’t submit a passport, you’ll need at least two documents from the IRS’s list of 13 acceptable forms of identification. These include a visa issued by the U.S. Department of State, a national identification card (with photo, address, date of birth, and expiration date), a foreign driver’s license, a foreign military ID, or a foreign voter’s registration card, among others.
For dependents under age 14, a photo ID isn’t required. Medical records can prove identity and foreign status for children under 6, and school records work for dependents under 24 who are students. All documents must be current and not expired at the time you submit your application.
Here’s the part that trips people up: you must submit original documents or certified copies issued directly by the granting agency. A regular photocopy won’t be accepted. The IRS will return your originals, but they’ll be out of your hands for several weeks during processing.
Where to Submit
You have three options for submitting Form W-7. You can mail it to the IRS along with your tax return and original supporting documents. Processing by mail generally takes seven weeks or longer. You can also visit an IRS Taxpayer Assistance Center in person, where an agent can review your original documents on the spot so you don’t have to mail them. The third option is using an IRS-authorized Certifying Acceptance Agent, a professional who can verify your documents and submit the application on your behalf.
How to Get a State Tax ID
A federal EIN does not cover state-level obligations. If your business collects sales tax, has employees, or owes other state-specific taxes, you’ll likely need a separate state tax identification number. Some states issue one number that covers all state taxes, while others assign different numbers for sales tax, payroll withholding, and unemployment insurance.
You apply through your state’s department of revenue or tax agency. Most states offer online applications that are free and processed within a few days. You’ll typically need your federal EIN, your business formation details, and information about your expected tax obligations. Apply for your state tax ID right after you register your business and receive your EIN, so you’re set up before your first sale or payroll run.
What the Application Costs
Every official tax ID application is free. The IRS charges nothing for an EIN or ITIN, and state tax agencies don’t charge for state tax ID numbers. If you land on a website asking for $79 or $149 to “file your EIN application,” that’s a third-party service, not the IRS. These sites fill out the same free form on your behalf and mark it up significantly. The IRS specifically warns against them. Go directly to IRS.gov for federal applications and to your state’s official tax agency website for state IDs.
How Long Each Application Takes
- EIN (online): Immediate. You walk away with your number in minutes.
- EIN (fax): About four business days.
- EIN (mail): Four to six weeks.
- ITIN (mail): Seven weeks or longer during peak filing season.
- ITIN (in person at a Taxpayer Assistance Center): Documents reviewed on the spot, but the number itself still takes several weeks to be assigned.
- State tax ID: Varies, but most online applications are processed within a few business days.
If you need your EIN quickly for a bank account or a contract, the online application is by far the best route. For ITINs, plan ahead and apply early in tax season so processing delays don’t cause you to miss your filing deadline.