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Short answer
An Illinois resale certificate is the Certificate of Resale a buyer signs to tell a seller that the goods are being bought for resale, not for an end user, so no sales tax is due on that purchase. The Illinois Department of Revenue treats a completed, signed Form CRT-61 as a valid certificate. The seller keeps a copy in its books and records, and the buyer should update the certificate at least every three years.
What an Illinois resale certificate is
The Department defines a Certificate of Resale as “a statement signed by the purchaser that indicates the merchandise purchased is for resale purposes only, not a sale to an end user, and therefore no tax is due.” Form CRT-61 is the Department’s own version. Other forms or statements can be used, but only if they contain the same information as Form CRT-61.
For medical and laboratory supply purchasing, this matters on both sides of the counter. A distributor that buys gloves, pipette tips or dressings to resell is the buyer who signs the certificate. A clinic or lab that buys the same items for its own use is an end user, and the resale route is not the one the Department describes for that purchase. For the wider picture, see resale certificates for medical supply distributors.
Certificate of Resale, Certificate of Registration and the E99 number
Illinois answers a common mix-up directly: three different documents are often treated as one. The comparison below follows the Department’s question-and-answer page on the difference between them.
| Document | What it is | Who has it |
|---|---|---|
| Certificate of Registration or License | Permission to do business in Illinois as a retailer, reseller or provider of services or goods that makes you responsible for taxes; it shows your Illinois Account ID or License Number | Businesses registered with the Department |
| Certificate of Resale (Form CRT-61) | A signed statement by the purchaser that the merchandise is for resale only, so no tax is due | The purchaser, for each supplier |
| Tax-exempt number | A number assigned to qualifying non-profit organizations so they can buy certain items exempt from tax; it begins with E99 followed by six digits | Qualifying non-profits |
A tax-exempt number is a separate thing from resale. For the exemption side, see the guide to a tax-exempt certificate for medical supplies.
Reseller or retailer registration
Illinois draws a line between registering as a reseller and registering as a retailer. A business registers as a reseller only if all of its sales are nontaxable, meaning every sale is to an exempt buyer or for resale, and it wants to buy exempt from registered Illinois suppliers. Registration can be done through MyTax Illinois, with Form REG-1, or through a regional office. The Department states that retailers making purchases for resale should not register as resellers; they complete Form CRT-61 instead.
A seller can check whether a buyer is a registered business with the look-up on the MyTax Illinois site, which the Department points to for verification. If you are starting out, the guide on how to become a medical supply reseller covers the business side.
Document checklist for supplier setup
Each item below comes from the Department’s Certificate of Resale page or its question-and-answer pages.
- A completed and signed Form CRT-61, or another form or statement that contains the same information as Form CRT-61.
- A copy of the certificate provided to the retailer or supplier.
- A refresh at least every three years, because the Department says certificates of resale should be updated at least that often.
- The seller’s own record: retailers must keep a certificate of resale in their books and records to document tax-exempt purchases for resale.
- If the buyer is a registered business, its Illinois Account ID or License Number from the Certificate of Registration, which is a different document from the resale certificate.
How this compares with other states
Resale paperwork differs by state: Illinois centers on a purchaser-signed statement with Form CRT-61 as the standard version. See how other states in this series handle it in the California resale certificate, Florida resale certificate and New Jersey resale certificate guides.
Common misunderstandings
- “My registration lets me buy tax-free.” A Certificate of Registration identifies you as a registered business and shows your Account ID. The resale exemption comes from the signed Certificate of Resale for the purchase.
- “A tax-exempt number and a resale certificate are the same.” The E99 number is assigned to qualifying non-profits. A resale certificate documents purchases for resale.
- “Any retailer should register as a reseller.” Illinois says retailers buying for resale complete Form CRT-61 instead of registering as resellers.
- “One certificate lasts forever.” The Department says certificates of resale should be updated at least every three years.
FAQ
What is an Illinois resale certificate?
It is a statement signed by the purchaser that the merchandise is for resale only, not a sale to an end user, so no tax is due. Form CRT-61 is the Department’s version.
Is Form CRT-61 required?
A completed and signed Form CRT-61 is a valid Certificate of Resale. Other forms or statements may be used only if they contain the same information as Form CRT-61.
How often should it be updated?
The Department says Certificates of Resale should be updated at least every three years.
Who keeps the certificate?
The buyer provides a copy to the retailer, and retailers must keep a certificate of resale in their books and records to document tax-exempt purchases for resale.
Does a resale certificate cover supplies a clinic or lab uses itself?
The Department defines the certificate as a statement that goods are for resale and not a sale to an end user. Items bought for your own use are not purchases for resale.
Sources
- Illinois Department of Revenue, Certificate of Resale, checked 2026-11-03.
- Illinois Department of Revenue, Difference between a Certificate of Registration, License, Certificate of Resale and tax-exempt number, checked 2026-11-03.
- Illinois Department of Revenue, Registering as a reseller, checked 2026-11-03.
This guide is general information, not tax or legal advice.
