Idaho ST-101 Sales Tax Resale or Exemption Certificate: How to Complete the Form

The Idaho ST-101 form is the state’s Sales Tax Resale or Exemption Certificate, and you complete it as the buyer to tell a seller why Idaho’s 6% sales tax should not be charged on a purchase. Fill in your identifying information, check the one exemption category that fits the transaction, sign and date it, and hand it to the seller. The seller keeps it on file as proof that skipping tax collection was legitimate. One properly completed form covers all future qualifying purchases from that same seller, because the certificate does not expire.

Download the current version from the Idaho State Tax Commission website before you start. The form is a single page, but every field on it matters. An incomplete certificate gives the seller no protection if the state audits the transaction, which usually means the seller will either reject the form or collect the tax anyway.

What Goes on the Form

Buyer and seller information. Your full legal name, street address, city, state, and ZIP go in the buyer block. The seller’s matching information goes in the seller block.
Federal EIN or driver’s license number. Enter your federal Employer Identification Number. If you don’t have one, use your driver’s license number and the state that issued it.
Idaho seller’s permit number. Enter it if you hold one. Wholesalers who make no retail sales and out-of-state retailers with no Idaho presence are not required to have a permit.
Exemption category. Check the single box in the section that matches your situation. Only one section per form.
Business description. Describe what your business does and what you sell, rent, lease, or produce. This is how the seller and the Tax Commission see that the exemption fits your line of work.
Signature, printed name, title, and date. Signing certifies that the information is true. The form warns that false information “can result in criminal and civil penalties.”¹

Which Box to Check

The ST-101 has four numbered sections, and your situation belongs in exactly one of them.

Section 1: Buying for Resale

This is the most common use. Check it when you’re buying goods you intend to sell, rent, or lease in the regular course of business, so the item isn’t taxed twice. Registered Idaho retailers enter their seller’s permit number. Out-of-state retailers with no Idaho presence check the designated box instead.² If you later use something you bought for resale, you owe use tax on the purchase price as of the date you first used it.³

Section 2: Producer Exemptions

Section 2 covers equipment, materials, and supplies used directly in production. The form lists the qualifying industries: broadcasting, logging, fabricating, mining, ranching, farming, manufacturing, processing, publishing free newspapers, and hunting or fishing operations.² Check the industry box and describe what you produce. The exemption generally applies to items consumed in production or that become part of the finished product. Office supplies and general overhead don’t qualify.

Section 3: Exempt Buyers

Some organizations are exempt no matter what they buy. Section 3 lists them: U.S. and Idaho government agencies, nonprofit hospitals, nonprofit schools, volunteer fire departments, qualifying senior citizen centers, museums, the Idaho Foodbank Warehouse, and others.² Many categories require federal income tax exemption under Section 501(c)(3) of the Internal Revenue Code. Volunteer fire departments, licensed emergency medical service agencies, and qualifying senior citizen centers all carry that requirement explicitly.⁴

Section 4: Other Exempt Goods and Buyers

Section 4 is the catch-all. It covers specific product types and narrow situations that don’t fit the first three sections: medical items, heating fuels, irrigation equipment used in agriculture, pollution control equipment, aerial tramway components, snowmaking and grooming equipment, research and development goods, certified data center purchases, and others. If your exemption rests on a statute that isn’t already reflected in sections 1 through 3, check “Other goods or entity exempt by law” and write in the specific Idaho Code section.²

If You’re Based Out of State

You can use the ST-101 even if your business sits outside Idaho and has no physical location, representatives, or employees in the state. In Section 1, check the “Out-of-state retailer; no Idaho business presence” box. Fill in every other required field: name, address, federal EIN or driver’s license number, business description, and signature.¹ You don’t need an Idaho seller’s permit for this.

How Long the Certificate Is Good For

The ST-101 does not expire. Once a seller has a properly completed form from you, it covers all qualifying purchases from that seller going forward, with no need to fill out a new one for each transaction. If your business information changes, such as a new address, new permit number, or a shift in product lines, give the seller an updated certificate so their records match.

What the Seller Does With It

Knowing what the seller needs on their end helps you deliver a form they’ll actually accept. The seller must review the certificate before accepting it, confirm every required field is filled in, and confirm you signed it. The form has to be “fully completed and signed” to be valid.¹ A seller can accept the form before the sale, at the sale, or at a reasonable time afterward.³

If you provided a seller’s permit number, expect the seller to verify it through the Idaho State Tax Commission’s online validation tool.⁵ A fabricated or mistyped number will come back as invalid, and the seller will charge the tax.

With a properly completed ST-101 on file, the seller has no duty to collect tax on that sale, even if your exemption claim later turns out to be invalid. Responsibility shifts entirely to the buyer in that case.³ That protection is why sellers are strict about the form being complete.

Contractors: Read This Before You Fill Anything Out

Contractors trip over the ST-101 more than any other group, because the rules work differently for them. Under Idaho law, contractors are treated as the end consumers of all goods they use to build, improve, repair, or alter real property. A contractor cannot give an ST-101 to a supplier for building materials, fixtures, or tools used on a construction job, even when the project is for a tax-exempt customer like a church, school, or government agency. The customer’s exempt status does not pass through to the contractor’s purchases.⁶

There is one narrow opening. Contractors who buy production equipment and parts for that equipment can purchase those items tax-free, provided the equipment does not become part of real property. Tools and equipment used to install production equipment are still taxable.⁶ For out-of-state jobs where materials are incorporated into real property in a state that doesn’t tax that work, the applicable form is the ST-103C, not the ST-101.

Penalties for Misuse

Handing a seller an ST-101 to dodge tax you legitimately owe is a misdemeanor in Idaho, punishable by a fine of up to $1,000, up to one year in jail, or both.⁷ The financial side adds up fast. A deficiency the Tax Commission attributes to negligence carries a 5% penalty on top of the unpaid tax. A deficiency attributed to intentional fraud carries a 50% penalty.⁸ Interest runs on top of all of it.

If a purchase doesn’t clearly fit one of the exemption categories on the form, pay the 6% tax. The cost of a bad exemption claim once back taxes, penalties, interest, and a possible misdemeanor are stacked together makes the upfront tax look cheap.

1
Idaho State Tax Commission. Sales Tax Resale or Exemption Certificate
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Idaho State Tax Commission. Form ST-101 Sales Tax Resale or Exemption Certificate
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Idaho State Legislature. Idaho Code 63-3622
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Idaho State Legislature. Idaho Code 63-3622O
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Idaho State Tax Commission. Seller’s Permits
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Idaho State Tax Commission. Contractors Working in Idaho
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Idaho State Tax Commission. Before the Tax Commission of the State of Idaho
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Idaho State Legislature. Idaho Code 63-3046