Illinois calls its sales tax permit the Certificate of Registration. It is free, and you apply on MyTax Illinois using Form REG-1. Online applications process in about one to two business days, per the Illinois Department of Revenue. Remote sellers must register once Illinois sales pass $100,000 in gross receipts.
This guide covers who must register, how to do it, what it costs, how long it takes, and the 2025 and 2026 rule changes that affect what you collect.
Key Takeaways
- Cost: $0. Registration through MyTax Illinois is free, per the Illinois Department of Revenue (IDOR).
- Timeline: About 1–2 business days online; IDOR advises allowing 6–8 weeks for a mailed paper Form REG-1.
- Threshold: Remote sellers hit economic nexus at $100,000 in cumulative Illinois gross receipts, per IDOR Bulletin FY 2026-12.
- Filing duty: IDOR assigns monthly, quarterly, or annual filing on Form ST-1, and zero returns are required.
What Is a Sales Tax Permit in Illinois?
The “sales tax permit” is officially the Certificate of Registration, issued by the Illinois Department of Revenue (IDOR). It authorizes your business to collect and remit Illinois sales and use tax. Searchers use “permit,” but IDOR issues a Certificate of Registration, per its retailers overview publication. The two terms mean the same thing.
Illinois has an unusual structure competitors skip. The state legally imposes Retailers’ Occupation Tax (ROT) on sellers and Use Tax on purchasers, per IDOR’s ROT guidance. “Sales tax” is the colloquial umbrella term. That distinction matters once sourcing rules apply, covered below.
Do You Need a Sales Tax Permit in Illinois?
Yes, if you have physical presence in Illinois, exceed the economic nexus threshold of $100,000 in cumulative gross receipts from Illinois sales in the preceding 12 months, or operate as a marketplace facilitator. The 200-transaction test was removed effective January 1, 2026, per IDOR Bulletin FY 2026-12, leaving gross receipts as the sole economic test.
| Nexus trigger | Who it catches | Source |
|---|---|---|
| Physical presence | Retailers with stores, offices, warehouses, or employees in Illinois | IDOR ROT guidance |
| Inventory in Illinois | Out-of-state sellers storing stock in Illinois fulfillment centers, including Fulfillment by Amazon (FBA) | IDOR ROT guidance |
| Economic nexus | Remote sellers with $100,000+ in cumulative Illinois gross receipts in the preceding 12 months | IDOR Bulletin FY 2026-12 |
| Marketplace facilitator | Platforms processing sales for third-party sellers into Illinois | IDOR Bulletin FY 2026-12 |
IDOR’s registration mandate is broader than sales tax alone. It applies to anyone conducting business in Illinois or with Illinois customers, including employers who withhold Illinois income tax, per the IDOR registration page.
How Do You Register for a Sales Tax Permit in Illinois?
IDOR offers three official methods: online through MyTax Illinois via “Register a New Business (Form REG-1),” by mailing a completed paper Form REG-1, or in person at an IDOR office to pick up and get help completing Form REG-1, per the IDOR registration page. Online is fastest and free.
Step 1: Gather Your Business Information
Collect your legal name, entity type, Federal Employer Identification Number (FEIN) or Social Security Number (SSN), business and mailing addresses, ownership details, North American Industry Classification System (NAICS) code, and projected monthly sales.
Step 2: Create a MyTax Illinois Account and Select “Register a New Business (Form REG-1)”
Create a MyTax Illinois account, then choose “Register a New Business (Form REG-1).” Form REG-1 is the Illinois Business Registration Application, a combined form covering multiple tax types, not a sales-tax-only application, per the IDOR registration page.
Step 3: Complete the Sales and Use Tax Sections
Enter your business structure, sales channels, remote seller or marketplace facilitator status, and expected taxable sales.
Step 4: Review and Submit
Check every field for accuracy before submitting. Incomplete entries delay processing.
Step 5: Receive Your Certificate of Registration
IDOR issues your Certificate of Registration electronically through MyTax Illinois or by mail. For registration questions, IDOR’s Central Registration Division is reachable at REV.CRD@Illinois.gov and 217-785-3707 (weekdays 8:00 a.m.–4:30 p.m.), with a forms and registration assistance line at 1-800-356-6302, per the IDOR registration page.
What Information Do You Need to Register?
You need your legal name and entity type, FEIN or SSN, business and mailing addresses, ownership details, NAICS code, start date of Illinois sales, projected monthly sales, and a declaration of remote seller status if you have no physical presence. Prepare these before you start to avoid delays.
Have the following ready:
- Existing Illinois Business Tax (IBT) number, if one is already assigned
- Marketplace facilitator status
- Business website and marketplace URLs
- Preferred filing contact for tax correspondence
Form REG-1 asks about payroll withholding and other taxes because it is a combined business registration application, not a sales-tax-only form. Answer only the sections that apply to your business.
How Much Does an Illinois Sales Tax Permit Cost?
It costs $0. Illinois charges no fee to register for a Certificate of Registration through MyTax Illinois, and there is no annual renewal fee, per the IDOR registration page. Staying free depends only on meeting your filing and payment obligations.
One nuance: IDOR may require a security bond from certain out-of-state or higher-risk registrants. This is a deposit against tax obligations, not a registration fee.
How Long Does It Take to Get an Illinois Sales Tax Permit?
Online applications through MyTax Illinois process fastest, in approximately one to two business days, per the IDOR registration page. Mailed paper Form REG-1 applications take far longer: IDOR states a paper registration takes four to six weeks to process and advises allowing six to eight weeks overall. Choose online when speed matters.
Once approved, your Certificate of Registration is downloadable directly from your MyTax Illinois account.
What Happens After You Register?
IDOR assigns you an Illinois Business Tax (IBT) number, the identifier IDOR uses for your business across tax types, issues your Certificate of Registration, and assigns a filing frequency, per its retailers overview publication. Three responsibilities begin immediately.
Display and Keep Your Certificate of Registration
Display the certificate at your Illinois place of business and retain digital and physical copies. This is a compliance requirement, not optional advice.
What Is Your Illinois Sales Tax Filing Frequency?
IDOR assigns monthly, quarterly, or annual filing based on your tax liability and notifies you. You file Form ST-1, the Sales and Use Tax and E911 Surcharge Return, and zero returns are required even with no sales.
| Filing frequency | When IDOR assigns it | Return | Due date | Source |
|---|---|---|---|---|
| Monthly | Higher taxable sales volume | Form ST-1 | 20th of the following month | IDOR |
| Quarterly | Moderate taxable sales | Form ST-1 | 20th of the month after each quarter | IDOR |
| Annual | Low taxable sales | Form ST-1 | January 20 | IDOR |
What Records Must You Keep?
Keep invoices, filed returns, and exemption certificates collected from exempt buyers, such as resale purchasers and exempt organizations. These documents support your exempt sales in an audit.
What Sales Tax Rates Do You Collect in Illinois?
The Illinois state rate is 6.25% on general merchandise, and local jurisdictions add more, pushing combined rates above 10% in Chicago, per IDOR’s ROT guidance. The 6.25% base breaks down into state, municipal, and county shares. Which local rate applies depends on seller type and sourcing, covered in the next section.
| Rate component | Rate | Applies to | Source |
|---|---|---|---|
| State | 5.00% | General merchandise | IDOR ROT guidance |
| Municipal | 1.00% | General merchandise | IDOR ROT guidance |
| County | 0.25% | General merchandise | IDOR ROT guidance |
| Combined base | 6.25% | General merchandise statewide | IDOR ROT guidance |
| Reduced rate | 1% | Qualifying drugs and medical appliances | IDOR ROT guidance |
The statewide 1% grocery tax was eliminated effective January 1, 2026, with a local reimposition option, detailed next.
What Changed for Illinois Sales Tax in 2025 and 2026?
Effective January 1, 2025, remote retailers and out-of-state sellers with Illinois physical presence must collect tax at destination-based rates, meaning the buyer’s location, per IDOR Bulletin FY 2025-10. This shifted affected sellers from Use Tax to destination-based ROT and changed how you calculate local rates on every Illinois shipment.
| Change | Effective date | What it means | Source |
|---|---|---|---|
| Destination-based ROT sourcing | January 1, 2025 | Retailers with Illinois physical presence selling from out-of-state collect ROT at the buyer’s delivery location rate (Public Act 103-983) | IDOR Bulletin FY 2025-10 |
| 200-transaction threshold removed | January 1, 2026 | $100,000 in cumulative gross receipts is the sole economic nexus test for remote retailers and marketplace facilitators (Public Act 104-0006) | IDOR Bulletin FY 2026-12 |
| Statewide 1% grocery tax eliminated | January 1, 2026 | The 1% state tax on groceries ended; municipalities may reimpose a 1% local grocery tax | IDOR ROT guidance |
What Do Out-of-State and Remote Sellers Need to Know?
Remote sellers register through the same MyTax Illinois Form REG-1 flow, declare remote seller status on the application, and since January 1, 2025 collect at the destination rate for each Illinois delivery address, per IDOR Bulletin FY 2025-10. Registration is required before your first taxable Illinois sale.
Three points matter for online sellers. If all your Illinois sales flow through a registered marketplace facilitator, the facilitator collects on those sales. Inventory in an Illinois fulfillment center creates physical nexus regardless of marketplace status. Registering late risks back taxes, penalties, and interest, so register as soon as you cross the threshold.
What Common Mistakes Should You Avoid When Registering?
The costliest errors are ignoring economic nexus, skipping marketplace facilitator registration, picking the wrong entity type, using an incorrect NAICS code, and collecting at the wrong local rate under the destination sourcing rules. Each one triggers delays, penalties, or under-collection.
- Ignoring economic nexus: Out-of-state sellers assume no storefront means no obligation, but $100,000 in Illinois gross receipts triggers registration.
- Skipping marketplace facilitator registration: Platforms that facilitate third-party sales must register and collect.
- Choosing the wrong entity type: A mismatched structure creates reporting and tax problems later.
- Using an incorrect NAICS code: Self-select the closest match; a wrong code can misstate your tax responsibilities.
- Collecting at the wrong local rate: Under destination sourcing, you charge the buyer’s location rate, not your own.
How Commenda Simplifies Illinois Sales Tax Compliance
Commenda’s global indirect tax software registers you in Illinois and every other state where you have nexus, monitors your physical and economic nexus, and handles Form ST-1 filings, including the zero returns Illinois requires. It tracks the destination-based ROT rate for each Illinois delivery address so you collect the right local rate every time.
Use the US nexus exposure guide to track where you cross thresholds, the Illinois sales tax state guide for state-specific rules, and the sales tax calculator for Illinois rate lookups. The calculator returns rates; the nexus guide is where you check exposure.
Book a demo to get a free nexus exposure assessment covering Illinois and every other state you sell into.
