Businesses that sell taxable goods in Illinois register with the Illinois Department of Revenue for a free Certificate of Registration, available online through MyTax Illinois. Online applicants should get their account ID by email in about 2 business days. Remote sellers must register once their Illinois sales reach $100,000 in the previous 12 months.
You must register with the Illinois Department of Revenue (IDOR) if you sell, lease, or rent tangible personal property at retail in Illinois. IDOR issues a Certificate of Registration, which is what Illinois calls a sales tax permit.
Illinois taxes prewritten ("canned") computer software as general merchandise. If you sell cloud-based software, check how Illinois taxes SaaS before you register.
Some Chicago taxes, such as the Personal Property Lease Transaction Tax, are administered by the City of Chicago's Department of Finance rather than IDOR.
If you have no physical presence in Illinois, you must register once you reach the Illinois economic nexus threshold: $100,000 or more in gross receipts from sales of tangible personal property to Illinois purchasers over the previous 12 months.
Illinois dropped its 200-transaction test on Jan. 1, 2026.
Count all sales of tangible personal property to Illinois purchasers, including exempt sales, except:
Retail sales and sales of service are measured separately, each against its own $100,000 threshold.
Check your sales at the end of every calendar quarter (March 31, June 30, Sept. 30, and Dec. 31) for the previous 12 months. If you meet the threshold, register and start collecting on the first day of the next quarter.
For example, if your Illinois sales for the 12 months ending June 30 reach $100,000, you need to collect from July 1.
Once you meet the threshold, you must collect and file for one full year, then check again. If you stay under $100,000, you aren't required to register, though you can register voluntarily to collect Illinois use tax.
If you crossed the threshold in the past and never registered, a voluntary disclosure agreement can help.
IDOR's Voluntary Disclosure Program limits the look-back period to four years and waives penalties if you pay the tax and interest within 60 days of billing. You owe any tax you collected but didn't remit for every period, even beyond four years.
You need a Certificate of Registration, regardless of sales volume, if you have physical nexus in Illinois. Physical presence includes:
Register before you make any sales. Since Jan. 1, 2025, out-of-state sellers with physical presence also owe Illinois retailers' occupation tax on orders they ship into Illinois from outside the state.
The one exception is inventory stored only in a marketplace's Illinois warehouse, covered in the next section.
Illinois's marketplace facilitator law makes marketplaces with $100,000 or more in Illinois sales responsible for collecting tax on their sellers' sales. A marketplace can certify this to you on Form CRT-63. Whether you still need your own registration depends on where you're based:
If a marketplace doesn't meet the $100,000 threshold, it doesn't collect for you. You're then responsible for the tax on those sales if you have physical presence in Illinois or meet the $100,000 threshold yourself.
If your only Illinois presence is inventory in a marketplace's Illinois warehouse, as with many Amazon FBA sellers, that inventory doesn't create physical presence. This only applies if the inventory fills marketplace orders only and the marketplace pays the tax on them.
If you also ship any of your own orders from that inventory, you have physical presence and need to register. Referral and affiliate contracts can also create sales tax nexus in Illinois.
If you're forming a corporation, S corporation, or LLC, register with the Illinois Secretary of State first. Corporations, S corporations, partnerships, and some LLCs also need a Federal Employer Identification Number (FEIN).
The checklists below follow Form REG-1, the Illinois Business Registration Application, which is the same application you complete online.
Who you list depends on your organization type. For example, LLCs list managers and members, and non-publicly traded corporations list the president, secretary, and treasurer. Use Schedule REG-1-O if you need more space.
The application also asks:
You can apply in three ways. Registering online through MyTax Illinois is the fastest option.
To apply on paper, complete and sign Form REG-1. You can email it to rev.crd@illinois.gov, fax it to 217-785-6013, or mail it to the Central Registration Division, PO Box 19030, Springfield, IL 62794-9030.
You can also visit an IDOR office to pick up Form REG-1 and get help completing it.
Go to MyTax Illinois. Under Register, select Register a New Business (Form REG-1).
You don't need a MyTax Illinois logon to register. Businesses create their logon after registration is processed.
Tip: MyTax Illinois times out after 30 minutes of inactivity, and unsaved information is lost. Use Save Draft as you go, and find your saved draft later under Retrieve a return, application, or payment in the Submissions panel.
On the Identify Your Business step, select your Organization Type. Then enter and confirm your FEIN, and enter your Legal Name and any DBA.
Select Next and follow the prompts. The application covers the same information as Form REG-1:
Review your answers and submit. There's no registration fee.
If you're an out-of-state seller registering for retail sales, the application prompts you to add at least one permanent or changing location where you expect to make sales, such as Chicago.
After that, remote retailers don't need to add or remove locations before filing, because MyTax Illinois shows all locations on one screen when you file.
IDOR emails your Illinois Account ID, in the format XXXX-XXXX, when it finishes processing your application. The email lists the tax types you're registered for and explains how to create a MyTax Illinois logon.
Wait 24 hours after that email, then select Sign Up on the MyTax Illinois homepage to create your logon. You'll verify the account with an owner, officer, or responsible party SSN, a PIN IDOR issued earlier, or account activity.
IDOR issues sales tax certificates electronically instead of printing and mailing them.
To print yours, log in and select View more account options in the ST-1 Sales/Use Tax panel, then View Account Letters in the Letters and Messages panel. The certificate is on the second page of the Business Authorization letter. If you can't print it, Central Registration can mail you a copy.
Display the certificate prominently at your place of business. If you register more than one location, IDOR issues a sub-certificate for each one.
Registering is free.
Under 35 ILCS 120/2a, IDOR may require a bond or other security before issuing your certificate. It can consider whether your owners or officers were tied to other businesses that defaulted or had their registrations revoked.
IDOR sets the amount based on the tax you're expected to owe. The cap is the lower of three times your average monthly tax liability or $50,000.
Accepted forms include a surety bond, a bank letter of credit, a bond signed by two personal sureties, and a bond secured by a bank account, certificate of deposit, stocks, or bonds.
Online registrations are the fastest. You should get an email with your account ID in about 2 business days, and your certificate within two weeks after your application is processed.
If you register in person at an IDOR office, you should get your account ID the same day. Paper applications take 6 to 8 weeks and are processed on a first-come, first-served basis.
An Illinois Certificate of Registration expires every year for retailers and every three years for resellers. How it renews depends on how you're registered.
If you're registered as a retailer and file sales tax returns, your certificate expires after one year and renews automatically. You don't need to do anything unless IDOR notifies you.
Automatic renewal only happens if you're up to date. IDOR doesn't renew if your account is in Collections or is missing information.
Warning: A missed return can cost you your certificate. Under 35 ILCS 120/2a, if you have unfiled returns or unpaid tax, IDOR notifies you at least 60 days before expiration, and the certificate won't renew unless you file and pay before it expires.
If all your sales are for resale, you will be registered as a reseller instead, and you must reapply every three years. IDOR mails a paper renewal packet 90 days before your certificate expires.
If nothing has changed, such as your address, contacts, or owners, you may be able to renew by emailing rev.crd@illinois.gov or calling Central Registration at 217-785-3707.
Charge Illinois sales tax on taxable sales: the 6.25% state rate on general merchandise plus any local taxes. Remote retailers and marketplaces use the rate at the delivery address.
When you register, IDOR assigns you to monthly or quarterly filing, and it reviews accounts each year. IDOR may change your frequency based on your average monthly liability:
You file Illinois sales tax returns online on Form ST-1 by the 20th of the month after each period. Annual returns are due Jan. 20.
You must file a return for every period, even if you have no sales. If you file and pay on time, you can keep a discount of 1.75% of the tax due or $5 a year, whichever is greater, up to $1,000 a month.
Retailer certificates renew each year automatically as long as you file and pay on time. Resellers renew every three years by paper packet, as covered above.
If you change your business structure, such as going from a sole proprietorship to a corporation, you need a new registration. Registration rules differ by state, and some require renewal fees.
Yes. Illinois calls its sales tax permit a Certificate of Registration. It allows you to do business in Illinois as a retailer or reseller and shows your Illinois Account ID.
No. IDOR issues the Certificate of Registration to you. A resale certificate is a statement a buyer signs to show a purchase is for resale, usually Form CRT-61, Certificate of Resale.
To buy inventory tax-free, you give your supplier a resale certificate with an active Illinois registration or resale number.
Yes. IDOR requires registration for sales for resale. If all your sales are for resale, IDOR registers you as a reseller rather than a retailer.
Yes. Anyone selling merchandise at fairs, festivals, pop-up events, flea markets, or craft shows must register, whether it's a full-time business or a hobby.
If you travel to events regularly, register as a "changing location" filer. At events that IDOR's Special Events Coordinator has registered, you'll get a separate form to report and pay the tax from that event.
It depends on where you're based. Out-of-state sellers don't need their own sales tax account if every Illinois sale goes through a marketplace that meets the $100,000 threshold and collects for them.
That holds even if Amazon stores your inventory in Illinois, as long as the inventory only fills Amazon orders. Sales through your own website aren't covered, and they count toward the $100,000 threshold.
Illinois-based sellers need a registration for any sales they make outside the marketplace.
Yes. Illinois certificates can't be transferred, so a new owner registers with a new Form REG-1.
Make sure Form CBS-1, Notice of Sale, Purchase, or Transfer of Business Assets, is filed with IDOR at least 10 business days before the sale. If it isn't, the buyer can be personally liable for the seller's unpaid Illinois taxes, up to the value of the property acquired.
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