How to Fill Out Illinois Form ST-587: Categories, Steps, and Filing

To fill out Illinois Form ST-587, work through the seven numbered steps on the certificate: identify the seller and yourself, describe the equipment, check the one exemption category that matches how you’ll use it, complete the blanket-certificate section only if it applies, and sign under penalty of perjury. You then hand the completed form to your seller, who keeps it on file. Do not mail Form ST-587 to the Illinois Department of Revenue.¹ The current blank form is available at tax.illinois.gov.

Filed correctly, the certificate lets you buy qualifying machinery and equipment without paying the state’s 6.25% Retailers’ Occupation Tax. Filed incorrectly, it can leave the seller collecting tax anyway, or worse, expose you to penalties down the line.

Pick Your Exemption Category First

Step 5 is the heart of the form. You must check exactly one of three boxes, and the box you choose has to match how the equipment will actually be used. Figure this out before you start writing.

Manufacturing and Assembling (Including Graphic Arts)

Check this box if the machinery or equipment will be used primarily in manufacturing or assembling tangible personal property for wholesale or retail sale or lease, or in graphic arts production such as printing presses, digital imaging systems, and finishing equipment. “Primarily” means more than 50% of the time in the qualifying process. Equipment used mostly for administration, sales, purchasing, accounting, marketing, or landscaping does not qualify, even if it sits inside a manufacturing facility. The exemption also reaches production chemicals, software that runs manufacturing equipment or controls the production process, and production-related property used within a manufacturing facility.² Items that must be titled or registered with a government agency, such as motor vehicles, are excluded.³

Production Agriculture

Check this box for machinery and equipment used primarily in commercial planting, harvesting, or raising of livestock and crops. Tractors, combines, irrigation systems, and specialized storage or sheltering structures qualify when the use threshold is met. Again, “primarily” means more than 50% of the time.⁴ A tractor bought for personal landscaping does not qualify. Your signature on the form certifies that the equipment will actually be put to qualifying agricultural use.⁵

Coal and Aggregate Mining

Check this box for equipment used primarily in coal and aggregate exploration, mining, off-highway hauling, processing, maintenance, and reclamation. Aggregate includes sand, gravel, stone, clay, industrial minerals, and other mineral solids besides coal. The 50%-plus use threshold applies here too, and motor vehicles required to be registered under the Illinois Vehicle Code are excluded. Consumables like chemicals, lubricants, coolants, reclamation materials, personal apparel, and fuel are not covered even when used at the mine site. The aggregate mining exemption itself is not permanent; Public Act 102-0700 extended it through July 1, 2028.⁶

Working Through the Seven Steps

Once you know which box you’re checking, the rest is mechanical.

Step 1 – Seller information. Enter the seller’s name, address, and phone number.

Step 2 – Purchaser information. Enter your name, address, phone number, and the date of purchase, then provide your Illinois account ID number, FEIN, or Social Security number. This is the field sellers most often flag. It is not a resale number; it is an identification number tied to you as the purchasing entity.¹ Without a valid number the seller has no way to verify your registration and will likely collect tax on the sale.

Step 3 – Lessee information. Fill this in only if you are buying the equipment to lease it to someone else. Enter the lessee’s name, address, and phone number. If you are not a lessor, leave the step blank.

Step 4 – Item description. Describe the machinery and equipment you’re buying, including serial numbers. This section covers both primary equipment and any repair or replacement parts. Be specific. Vague descriptions cause problems if the seller is later audited and the exemption is questioned.

Step 5 – Exemption category. Check the one box you identified above: manufacturing and assembling (including graphic arts), production agriculture, or coal and aggregate mining.

Step 6 – Blanket certificate. Skip this step for a one-off purchase. Complete it only if you want the form to cover future purchases from the same seller (see below).

Step 7 – Signature. Sign and date. Your signature certifies under penalty of perjury that the information on the certificate is true, correct, and complete.¹

Single Purchase or Blanket Certificate

A single-purchase certificate covers one transaction. Fill out the form, hand it over, done. A blanket certificate covers all qualifying future purchases from the same seller, so you don’t fill out a fresh ST-587 every time.⁷

Step 6 offers two blanket options. You can certify that all of your purchases from that seller qualify for the exemption, or you can specify a percentage of purchases that qualify. The percentage option fits situations where you buy both exempt machinery and non-exempt supplies from the same vendor. You still have to check a category in Step 5; the blanket certificate does not work without it.¹

Update blanket certificates at least every three years, and sooner if your equipment use, entity structure, or account ID changes.¹

What to Do With the Completed Form

Give the finished ST-587 to your seller at the time of the transaction. For remote or online purchases, you can send it electronically. The seller keeps the original as proof that no tax was due. Again, do not mail the form to the Illinois Department of Revenue.¹ The Department may request the certificate from the seller in an audit, but it is the seller’s file that holds it.

You are not strictly required to use the ST-587 itself. Illinois will accept other documentation as long as it contains the same core information: the seller’s and purchaser’s names, your identification number, a description of the items, and a statement that the property is being purchased for qualifying use.⁸ The ST-587 is the standard form because it guarantees those elements are present.

Keep Your Own Copy

Purchasers should keep a duplicate of every ST-587 they submit. If the Department later questions why tax wasn’t paid on a piece of equipment, your copy shortens the conversation considerably. For blanket certificates, keep the copy alongside records showing what share of your purchases from that seller actually went to exempt use, so you can back up the percentage you certified.

What Happens If You Get It Wrong

The signature line is not a formality. Under Illinois law, it is a Class 4 felony to misrepresent your registration number to a seller, or to use your number to make a seller believe you’re buying for an exempt purpose when you know you aren’t.⁹

The tax exposure is separate from the criminal exposure. If you buy equipment tax-free and later convert it to a non-qualifying use, such as pulling a machine off the production floor and reassigning it to general office work, you owe tax on the fair market value at the time of conversion. For aggregate mining equipment, the administrative code states the rule directly: equipment initially put to a qualifying use that gets converted to a non-qualifying use before serving at least half of its useful life becomes taxable at conversion.⁶ The Department can also assess a 50% fraud penalty on the tax deficiency when misuse was intentional. Documenting how you actually use the equipment, year over year, is the best protection against both an honest conversion problem and any suggestion that the original exemption was claimed in bad faith.

1
Illinois Department of Revenue. ST-587 Exemption Certificate
2
Legal Information Institute. Illinois Administrative Code tit. 86, 130.330 – Manufacturing Machinery and Equipment
3
FindLaw. Illinois Code 35 ILCS 120/2-45 – Manufacturing and Assembly Exemption
4
Illinois General Assembly. 86 Illinois Administrative Code 130.305 – Farm Machinery and Equipment
5
Illinois General Assembly. Illinois Code 35 ILCS 120/2-5 – Exemptions
6
Legal Information Institute. Illinois Administrative Code tit. 86, 130.351 – Aggregate Exploration, Mining, and Reclamation Equipment
7
Illinois Department of Revenue. When Is a Blanket Certificate Used?
8
Illinois Department of Revenue. How Do I Properly Document an Exempt Sale or Purchase of Machinery and Equipment Used for Manufacturing, Production Agriculture, or Coal and Aggregate Mining?
9
Illinois General Assembly. Illinois Code 35 ILCS 120/13