How to Find an EIN Number in Illinois

Understanding which state and federal TINs your Illinois business needs and how to get them is important to ensure compliance with state and federal laws.

This guide explains the different types of TINs and what businesses need them, how to get federal and Illinois state TINs, and how to find your business’ EIN. 

What is an Illinois tax ID number, and who needs one?

An Illinois TIN is an account ID number issued by the Illinois Department of Revenue (IDOR) that is used for state tax purposes. Most businesses in Illinois will receive an account ID number when they register with IDOR. The type of Illinois taxpayer ID number your business needs is determined by your business activities.

Illinois businesses with employees, corporations, partnerships, and certain sole proprietors will also need a federal tax ID number, also known as an employer identification number (EIN), to comply with federal tax requirements. 

Types of tax ID numbers for businesses in Illinois

Businesses in Illinois may need the following federal and state TINs:

• Social Security number (SSN): The Social Security Administration (SSA) issues SSNs. Many sole proprietors can use their SSNs to file taxes. 
• EIN: The IRS issues EINs. Certain businesses—including corporations, partnerships, and businesses with employees—are required to have an EIN. 
• ITIN: Sole proprietors who are ineligible for an SSN (such as certain nonresident and resident aliens) can use an ITIN to file taxes. 
• Illinois state TIN: IDOR issues Illinois TINs based on the types of taxes a business registers for.

Federal employer identification number 

The IRS issues EINs for federal tax purposes. An EIN can be used for business activities such as paying taxes, running payroll, and setting up a business bank account.

The IRS requires the following types of businesses to obtain an EIN:

• Businesses with employees
• Businesses that are required to pay employment, excise, or alcohol, tobacco, and firearms taxes
• Businesses that withhold taxes on income (other than wages) that is paid to a nonresident alien
• Corporations
• Limited liability companies (LLCs)
• Partnerships

The IRS also requires estates, farmers’ cooperatives, real estate mortgage investment conduits (REMICs), retirement plans or individual retirement accounts (IRAs), certain trusts, and tax-exempt organizations to have an EIN. 

Even if the IRS doesn’t require you to have an EIN, you may still want to get an EIN for business purposes, such as opening a business bank account. 

Illinois Department of Revenue (IDOR) account ID

IDOR issues account ID numbers for businesses operating in Illinois. Account ID numbers are used for state tax purposes, such as paying sales and use tax, withholding tax, and business income tax. If you conduct business in Illinois or with Illinois customers, you will likely need to register with IDOR. 

If you register online, you will get an email once your application has been processed letting you know which tax types you registered for and the associated account numbers. 

How to find your company’s EIN

The following methods can help you find your business’ EIN.

• Check IRS notices: The IRS issues a computer-generated notice that serves as a receipt of your EIN. 
• Check business tax filings: Your federal tax returns should contain your EIN. 
• Talk to your bank: If you used your EIN to open a business bank account, your bank’s customer service may be able to help find your EIN. 
• Contact business licensing and permitting agencies: Contact the licensing agency where you applied for a business license or permit to get help finding your EIN. 
• Contact the IRS: Call the IRS Business and Specialty Tax Line (800-829-4933) to request your EIN.

How to get a tax ID number in Illinois

Here’s a breakdown of how to get federal and state TINs in Illinois. 

Obtaining a federal EIN

There are a few different ways to get a federal EIN:

• Apply online: You can get an EIN immediately by applying online on the IRS website. 
• Apply by fax: You can submit your EIN application via fax to 855-641-6935. The processing time for faxed applications is four business days. 
• Apply via mail: You can also send your EIN application to the IRS by mail. The processing time for EIN applications submitted through the mail is approximately four weeks. 
• Request an EIN over the phone: International applicants can apply for an EIN by calling 267-941-1099.
• Use an EIN service: If you don’t want to deal with the hassle of applying for an EIN, you can use an EIN service. With LegalZoom’s EIN service, all you have to do is answer a few questions about your business, and we’ll complete and submit your EIN application for you and send you official confirmation of your EIN.

Whichever method you use, you will need information about your business entity, the name and SSN or TIN of the responsible party in charge of your business, and signed authorization to apply (if you are a third-party designee). 

Registering for an IDOR account ID

Most businesses in Illinois must register with IDOR. Illinois businesses are required to register with IDOR or the Illinois Department of Employment Security (IDES) before they can make tax-exempt sales or purchases or hire employees. After you register, you will get a Certificate of Registration or License and an Illinois business tax number (if applicable).

There are three ways to register with IDOR:

1. Online via MyTax Illinois. Click Register a New Business (Form REG-1). The processing time for online registration applications is approximately one to two business days. Registration with the Illinois Department of Employment Security (IDES) or the Illinois Liquor Control Commission can also be done through MyTax Illinois.
2. By mail. You can print, fill out, and mail Form REG-1, Illinois Business Registration Application, to the address listed on the form. You can also request a paper registration form by calling 800-356-6302. The processing time for paper registration applications is typically four to eight weeks. 
3. In person. Visit one of IDOR’s offices to get a paper registration form and in-person help with your application. 

You may need to submit one of the following corresponding registration schedules based on your business activities:

• Schedule REG-1-A, Liquor Information
• Schedule REG-1-C, Cigarette and Tobacco Products Information
• Schedule REG-1-D, Electricity Tax Self-Assessing Purchaser
• Schedule REG-1-G, Gas Use Tax Self-Assessing Purchaser
• Schedule REG-1-L, Illinois Business Site Location Information
• Schedule REG-1-MR, Illinois Cigarette Manufacturer’s Representative
• Schedule REG-1-O, Owner and Officer Information
• Schedule REG-1-R, Responsible Party Information
• Schedule REG-1-T, Telecommunications Tax Location Information

You will also need to figure out the tax types you need to register for. 

Common tax types include the following:

• Withholding income tax. Businesses with Illinois employees may need withholding taxes and/or unemployment insurance taken out of their employees’ paychecks. 
• Sales and use taxes. Businesses that sell, lease, or rent tangible goods must register to collect and pay sales and use taxes. 
• Business income tax. Corporations, S corporations, partnerships, and LLCs must register for business income tax in Illinois.

Getting an Illinois corporate registration number

When you register a business with the Illinois Secretary of State you will get an Illinois file number. The Illinois file number isn’t a TIN, but is used for identifying businesses in the state. You can look up your business’ file number on the Illinois Secretary of State’s Business Entity Search page. 

Compliance and reporting requirements in Illinois

Once you have your required TINs, you will need to take steps to comply with federal and state regulations. 

Federal tax obligations

It’s important to report and pay federal income taxes on time. You can check the IRS’ General Tax Calendar, Employer’s Tax Calendar, and Excise Tax Calendar to determine applicable tax deadlines for your individual business. 

State tax obligations

You will need to file state taxes and make payments on time to comply with Illinois law. Most Illinois business tax forms can be filed using MyTax Illinois. Businesses that are required to make estimated tax payments can submit payments online through their MyTax Illinois account or ACH Credit or by mailing in a payment voucher.

Record-keeping

It’s essential to keep track of your tax identification numbers and maintain your business tax records, books, and any correspondence with state or federal agencies for compliance and audit purposes.

One way to do this on the state level is by creating a MyTax Illinois account after you register with IDOR. You can file and pay taxes online via your MyTax Illinois account and keep addresses, contact info, and officer and member information stored in one place.

FAQs 

Do I need multiple TINs for my business?

You may need multiple TINs for your business, depending on your business type and activities.

How do I find my employer’s EIN?

You can find your employer’s EIN by checking your W-2 form, searching the U.S. Securities and Exchange Commission’s (SEC) Electronic Data Gathering, Analysis, and Retrieval (EDGAR) system, or by asking your employer directly. 

How do I find other companies’ EINs?

You may be able to find other companies’ EINs through the following methods:

• Search the SEC’s EDGAR system
• Conduct a Tax Exempt Organization Search on the IRS website
• Call the company and ask for its EIN

How much does an EIN cost in Illinois?

You can get an EIN for free if you apply directly through the IRS. If you’d rather have the convenience of an EIN service, LegalZoom’s costs $79.