The state of Illinois raises revenue by imposing a sales tax on products and services purchased in Illinois. Businesses of all sizes, including sole proprietors up to large corporations, need to register for sales-tax purposes and remit tax on Illinois sales. The Illinois Department of Revenue processes applications and issues registration certificates and taxpayer ID numbers for Illinois businesses. Applicants can either apply online or use a paper form to apply for an Illinois sales-tax ID number.
Use the checklist on the Internal Revenue Service (IRS) "Do You Need an EIN?" page to determine whether your business needs a federal employer identification number (see Resources). Call the IRS at 800-829-4933 to obtain a free EIN right over the phone if you need one. If you do not need an EIN, then you may use your social security number when applying for an Illinois sales-tax ID number.
Access the "Illinois Business Registration Application" (REG-1) form (see References 1). Use this form to apply for an Illinois taxpayer ID number for collecting and submitting sales tax to the Illinois Department of Revenue. You may also call 800-356-6302 to request an application or other tax forms. Alternatively, you may use the Illinois Business Gateway online service to fill out the application for an Illinois tax ID (see Resources).
Fill out the tax-ID application. Note which additional forms you need as you complete this application. Access Schedule REG-1-O if you need more space to report owners, officers, general managers and members of a limited liability company (see Resources). Access Schedule REG-1-L if you are a new business that intends to do business from an Illinois location (see Resources). Access Schedule REG-1-R if you intend to have a third party submitting your sales-tax forms and taxes on your behalf (see Resources).
Sign and date the sales-tax ID application and fill out all the schedules required by your situation. Attach all schedules to the main application.
Mail in the application and schedules or use the regional office directory to find a tax office for personally delivering the application (see References 2). As of 2010, Illinois does not charge a fee to get a sales-tax ID number. Use the following address when mailing in the application:
Central Registration Division Illinois Department Of Revenue P.O. Box 19476 Springfield, IL 62794-9476
You may receive a sales-tax ID number in about one to two days when applying online. Wait six to eight weeks if sending in a paper application.
You must display your registration certificate in your place of business after receiving it from the department.
Call 217-785-3707 if you need to report changes after registration. You do not need to fill out a new application to report changes to a registered business.