Kansas Farm Tax Exempt Form ST-28F: Coverage, Filing, and Penalties

Kansas farmers, ranchers, and aquaculture producers use the Kansas farm tax exempt Form ST-28F, the Agricultural Exemption Certificate issued by the Kansas Department of Revenue, to buy qualifying machinery, repair parts, and maintenance labor without paying state and local sales tax. You complete the form, hand it to the seller at the point of sale, and the seller keeps it on file to justify the tax-free transaction. The exemption sits in K.S.A. 79-3606(t), and used correctly it can save a working operation thousands of dollars a year.¹

Who Qualifies

The exemption is for commercial agricultural producers. Kansas defines farming or ranching as any activity ordinary and necessary for growing or raising agricultural products, operating a feedlot, or performing farm and ranch work for hire. Nurseries and Christmas tree operations qualify under the statute.¹ Sole proprietorships, partnerships, corporations, and LLCs can all use it as long as the operation fits that definition.

Personal use does not qualify. Kansas expressly excludes raising agricultural products for personal consumption, processing food or dairy, off-farm grain storage and marketing, operating a stockyard or slaughterhouse, and retailing farm supplies.² A few head of cattle on land used mainly as a weekend retreat is the classic fact pattern that fails.

Kansas does not set a specific profit threshold, but the federal profit-motive test often comes up on audit. The IRS presumes an activity is a business rather than a hobby if it turns a profit in at least three of five consecutive years, or two of seven for horse breeding and similar equine activities.³ Keeping real books and putting real time into the operation is what separates a farm from a hobby.

What Purchases the ST-28F Covers

K.S.A. 79-3606(t) exempts three things from Kansas sales tax:¹

The purchase, lease, or rental of farm, ranch, or aquaculture machinery and equipment
Repair and replacement parts for that machinery and equipment
Labor services to repair and maintain that machinery and equipment

The qualifying list is long. Tractors, combines, irrigation systems, balers, grain drills, milking machines, portable feeders, barn ventilators, manure spreaders, and bulk milk tanks all qualify. So do fencing materials, portable corral panels, and head gates used directly in production. Fluids that keep equipment running, including antifreeze, hydraulic fluid, and lubricating oils, are also exempt when purchased for farm machinery.²

Precision farming technology is written into the statute: soil testing sensors, yield monitors, GPS and mapping systems, guidance systems, computers, monitors, software, modems, data communications equipment, and the mounting hardware, wiring, and antennas that go with them. This equipment qualifies whether portable or permanently mounted.¹

The same ST-28F is used for a handful of related agricultural exemptions, each with its own checkbox on the form:⁴

Agricultural animals such as cattle, hogs, sheep, poultry, and aquatic animals sold for production or breeding, under K.S.A. 79-3606(o)
Propane used for an agricultural purpose, under K.S.A. 79-3606(w)
Seeds, tree seedlings, fertilizers, insecticides, herbicides, and related services used to prevent soil erosion on agricultural land, under K.S.A. 79-3606(mm)

What the ST-28F Does Not Cover

Some property is excluded even when you use it every day on the farm. Buildings, building materials, and silos are not farm machinery and equipment under the statute. Passenger vehicles, trucks, truck tractors, trailers, semitrailers, and pole trailers are all excluded, with a narrow exception for farm trailers designed and used primarily for farm purposes. ATVs and motorcycles are explicitly excluded.² A pickup used to haul feed does not qualify, no matter how central it is to daily work.

Work-Site Utility Vehicles

A work-site utility vehicle is the one meaningful vehicle exception, and it comes with strict rules. The vehicle must meet every one of five physical specifications, and Part C of the ST-28F asks you to check all five:⁴

At least 48 inches wide
Unladen weight, including fuel, over 800 pounds
Four or more non-highway tires
Bench or bucket-type seating
A bed or cargo box for hauling materials

Miss one spec and the vehicle does not qualify. The vehicle must also be used exclusively in farming, ranching, or aquaculture production. The form lists disqualifying uses explicitly: hunting, trail riding, fishing, mudding, transporting passengers for non-farm purposes, and any recreational activity.⁴ If the kids take the side-by-side out on weekends, you owe the tax.

How to Fill Out and Deliver the Form

Download the ST-28F PDF from the Kansas Department of Revenue website. Every purchaser completes Part A and Part D. Parts B and C are only required for specific categories such as ingredient parts or work-site utility vehicles.⁴

Part A asks for the seller’s name and address, the purchaser’s name and address, and a description of what is being bought. You then select the exemption category, whether that is farm machinery and equipment under K.S.A. 79-3606(t), agricultural animals under 79-3606(o), or propane under 79-3606(w). Be specific in the description field. “Replacement hydraulic hoses for John Deere 8R combine” gives the retailer what they need; “parts” does not.

Part D is the certification and signature. By signing, you attest that the property will be used exclusively in farming, ranching, or aquaculture production, and you accept liability for the unpaid sales tax, penalties, and interest if the property is later put to non-exempt use.⁴

You give the completed form to the retailer at the point of sale. The retailer keeps the signed original on file. There is no filing with the Department of Revenue at the time of purchase; the certificate is your justification for the tax-free transaction if the seller is later audited.

Keep Your Own Copies

Kansas retailers are required to retain exemption certificates for at least three years from the date of sale, matching the three-year sales tax record retention rule under K.S.A. 79-3609. If the Department audits the seller and finds a certificate missing or incomplete, the retailer has 120 days from the Director of Taxation’s notice to get a corrected certificate for the affected sales.⁵ Keep your own copy of every ST-28F you sign so you can respond quickly if the retailer contacts you.

Penalties for Misusing the Certificate

Using an exemption certificate to dodge tax on personal purchases is a crime. Under K.S.A. 79-3651(e), issuing an exemption certificate to unlawfully avoid tax for business or personal gain is a misdemeanor punishable by a fine of up to $1,000, up to one year in jail, or both.⁶ The Director of Taxation can also add a civil penalty of $250 or ten times the tax due on each fraudulent transaction, whichever is greater, on top of the back tax and interest.

Buying From Out-of-State Sellers

For purchases from out-of-state vendors, the Streamlined Sales Tax Certificate of Exemption (SSTGB Form F0003) is often more practical than the Kansas-specific ST-28F. Kansas is a member of the Streamlined Sales Tax Agreement, and the SST certificate is accepted in all member states.⁷ To claim the agricultural exemption on that form, check “Agricultural Production” in Section 4 and supply the tax ID number the state requires.

Unless you specifically check the single-purchase box, the SST certificate works as a blanket certificate for ongoing purchases from the same seller. It stays valid until cancelled, so long as purchases occur no more than 12 months apart.⁷ Not every member state allows every exemption on the form, so confirm with the seller that the agricultural production exemption applies in their state before treating the purchase as tax-free.

1
Kansas Office of Revisor of Statutes. Kansas Code 79-3606 – Exempt Sales
2
Kansas Department of Revenue. Pub. 1550 Business Taxes for Agricultural Industries
3
Internal Revenue Service. About Publication 225, Farmer’s Tax Guide
4
Kansas Department of Revenue. Agricultural Exemption Certificate
5
Kansas Department of Revenue. Pub. KS-1520 Exemption Certificates
6
Kansas Legislature. Kansas Code 79-3651 – Retailers Sales Tax Act
7
Streamlined Sales Tax Governing Board. Streamlined Sales Tax Certificate of Exemption