Kentucky Sales Tax Exemption Certificate: Forms, Uses, and Recordkeeping

A Kentucky sales tax exemption certificate is the form a qualifying buyer gives a seller to purchase goods or services without paying the state’s six percent sales and use tax. The form you use depends on why you qualify: reselling inventory, running a nonprofit, farming, buying across state lines, or acquiring industrial machinery. Fill it out completely, hand it to the seller at the time of sale, and keep a copy — the Department of Revenue can ask to see it years later, and misusing one is a criminal matter, not just an accounting one.¹

Which Certificate Matches Your Situation

Kentucky uses a different form for each type of exempt buyer. Using the wrong one is the same as using none at all.

Form 51A105, Resale Certificate. For businesses buying tangible personal property, digital property, or taxable services they will resell in the regular course of business.²
Form 51A126, Purchase Exemption Certificate. For Kentucky-resident nonprofit educational, charitable, or religious institutions and Kentucky historical sites buying property or services used solely within their exempt function.³
Form 51A158, Farm Exemption Certificate. For farmers buying qualifying supplies, equipment, or livestock exempt under KRS 139.480.⁴
Form 51A260, Streamlined Sales Tax Certificate of Exemption. A multi-state form accepted by Kentucky and every other Streamlined Sales Tax member state.¹
Form 51A111, Certificate of Exemption for Machinery for New and Expanded Industry. For eligible industrial machinery purchases.

Specialized versions exist for narrower situations. Form 51A383, for example, covers building materials bought by construction contractors working on sewer or water projects with a government agency. All forms are on the Kentucky Department of Revenue website.

What Goes on the Certificate

Every form asks for the same basic building blocks: who the buyer is, what qualifies them for the exemption, a description of the property being purchased, and a signature with a date. An unsigned certificate is invalid, and a seller who accepts one absorbs the uncollected tax.³

On the Resale Certificate, the purchaser certifies they hold a valid Kentucky Sales and Use Tax Permit and provides their account number.² An out-of-state retailer who isn’t required to hold a Kentucky permit uses their home state’s retail number instead and notes on the certificate that they are an out-of-state retailer.⁵ The description of the buyer’s business activity has to make sense against the purchase: a restaurant supply company buying kitchen equipment for resale is straightforward; the same company buying office furniture on a resale certificate is the kind of mismatch that surfaces in an audit.

Two hard restrictions are worth flagging. Contractors and other persons registered under a consumer account number in the 900,000 series cannot issue a resale certificate for any purchase, and sellers who accept one from those buyers are liable for the unpaid tax.² Construction contractors also cannot use a nonprofit’s Purchase Exemption Certificate to buy materials for a job at an exempt institution. The exemption belongs to the institution, not to whoever is working for it.³

Farm buyers have an added step. Since January 1, 2022, farmers must obtain an Agriculture Exemption Number from the Department of Revenue before making tax-exempt purchases, and that number must appear on Form 51A158 (and the related Form 51A159).⁶ Farmers apply for the number using Form 51A800.

What Purchases Actually Qualify

Having the right form doesn’t help if the purchase itself doesn’t fit the exemption.

Resale

The property must be genuinely resold in the buyer’s regular business, or used in manufacturing or industrial processing of goods that will themselves be sold.² Office supplies, break room snacks, and anything the business consumes internally do not qualify, even if the buyer holds a valid resale certificate. Personal or internal use of resale-exempt purchases is exactly what triggers penalties.

Farming

KRS 139.480 exempts livestock raised for food production when sold for breeding or dairy purposes, feed and feed additives for food-producing livestock, and farm machinery used exclusively and directly in farming operations such as tilling soil, raising livestock for sale, or producing milk.⁷ The machinery exemption covers attachments, repair parts, and replacement parts, but automobiles, trucks, and most trailers are excluded. If a farmer later uses exempt property for a non-exempt purpose, they owe the sales tax as if they had made a retail sale of that property at its cost.⁴

Nonprofits

Under KRS 139.495, a Kentucky-resident nonprofit educational, charitable, or religious institution with 501(c)(3) status pays no sales tax on tangible personal property, digital property, or services used solely within its exempt function. The exemption also reaches single-member LLCs wholly owned by a qualifying 501(c)(3) and disregarded for federal tax purposes.⁸ Personal purchases by staff or volunteers using the organization’s certificate are not covered and expose the individual to penalties.

Blanket vs. Single-Purchase Certificates

A resale certificate can be issued for one transaction or as a blanket certificate covering all future qualifying purchases from the same seller. The blanket version must include a general description of the kinds of property the buyer normally purchases for resale, and it stays valid as long as the purchaser’s business operations haven’t fundamentally changed and the purchases continue to be the kind of property the buyer usually resells.⁹ For a regular vendor relationship, one blanket certificate replaces dozens of individual forms a year.

Buying Across State Lines

Businesses operating in multiple states can use the Streamlined Sales Tax Certificate of Exemption (SSTGB Form F0003, listed in Kentucky as Form 51A260) across all 24 member states.¹⁰ Unless the single-purchase box is checked, it functions as a blanket certificate and stays effective until the purchaser cancels it, provided purchases from that seller are no more than 12 months apart.¹¹ The buyer doesn’t need to be registered through the Streamlined Sales Tax Registration System to use the form, but must enter the appropriate state ID number if the claiming state requires registration. Not every exemption listed on the form applies in every state, so the buyer confirms eligibility for each state where the exemption is claimed.

Sellers get strong protection: a fully completed certificate received within 90 days of the sale generally shields the seller from tax, interest, and penalties if the purchaser turns out to have claimed the exemption improperly, unless the seller acted fraudulently or solicited unlawful exemption claims.¹¹

The Seller’s Side

Hand the completed certificate to the seller at the time of purchase. A seller who accepts an exemption certificate in good faith is protected from liability if the exemption is later found invalid. Under KRS 139.270, when the Department of Revenue determines that the seller properly obtained the certificate but the purchaser misused the exemption, the department pursues the purchaser for the tax, not the seller.¹²

That protection disappears when the seller knowingly accepts a fraudulent or incomplete form. On the Farm Exemption Certificate, the warning is explicit: failing to obtain a completed certificate makes the seller liable for the tax.⁴ The same logic runs through the other forms. Missing signatures, blank account numbers, and vague descriptions of the buyer’s business are the red flags to catch before the sale closes.

Keep the Certificate for Four Years

Kentucky requires every seller and retailer to keep records, receipts, invoices, and other relevant paperwork in whatever form the Department of Revenue requires, and to hold them for at least four years from the date they were created, unless the department gives written authorization to destroy them sooner.¹³ Exemption certificates sit squarely inside that rule. If an auditor asks for the certificate behind a tax-free sale from three years ago and it isn’t there, the seller can be assessed for the uncollected tax plus interest. The four-year clock runs from when the record was made, so build in a buffer.

Penalties for Misuse

Kentucky treats exemption certificate abuse as a criminal matter. Anyone who executes a resale certificate knowing at the time of purchase that the property will not actually be resold, or who uses an exemption certificate knowing they are not entitled to exempt status or do not intend to use the property as required, is guilty of a Class B misdemeanor.¹⁴ The same charge applies to misuse of an agriculture exemption license number or a Streamlined Sales Tax certificate.

On top of that, the Department of Revenue will hold the purchaser liable for the full tax that should have been collected, plus any applicable penalties under KRS 139.990.¹² For nonprofits, the Purchase Exemption Certificate spells out that any official or employee who uses the certificate for personal purchases faces penalties under KRS 139.990 and other applicable laws.³ The criminal penalty turns on knowledge at the time the certificate was signed, but the tax liability itself attaches whether the misuse was intentional or accidental.

1
Department of Revenue. Sales and Use Tax
2
Kentucky Department of Revenue. Form 51A105 – Resale Certificate
3
Kentucky Department of Revenue. Form 51A126 – Purchase Exemption Certificate
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Kentucky Department of Revenue. Form 51A158 – Farm Exemption Certificate
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Kentucky Department of Revenue. FAQ Sales and Use Tax
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Department of Revenue. Agriculture Exemption Numbers
7
Kentucky Legislative Research Commission. Kentucky Code 139.480 – Property Exempt
8
Justia Law. Kentucky Revised Statutes 139.495 – Application of Taxes to Resident Nonprofit Institutions and to Certain Limited Liability Companies
9
Cornell Law Institute. Kentucky Code 103 KAR 31:111 – Sales and Purchases for Resale
10
Streamlined Sales Tax Governing Board. Exemptions
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Streamlined Sales Tax Governing Board. Streamlined Sales Tax Certificate of Exemption
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Kentucky Legislative Research Commission. Kentucky Code 139.270 – Resale Certificate and Certificates of Exemption
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Kentucky Legislative Research Commission. Kentucky Code 139.720 – Records Required to Be Kept – For How Long
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Kentucky Legislative Research Commission. Kentucky Code 139.990 – Penalties