How to Fill Out the Kansas ST-28F: Agricultural Exemption Certificate

The Kansas ST-28F Agricultural Exemption Certificate is the form you give a vendor so they don’t charge sales tax on qualifying farm purchases. Download the fillable PDF from the Kansas Department of Revenue at ksrevenue.gov, fill in the seller and buyer information, describe what you’re buying, check the box in Part A that matches the type of exemption, complete Part B or Part C if they apply, then sign and hand it to the seller at or before purchase.¹ The form asks for less than you might expect: no tax ID number, no EIN, no Social Security number. What matters is that the description is specific and the exemption category is right.

Who Can Use the Certificate

You qualify if you’re producing food, fiber, fur, or other agricultural products for sale. Commercial intent is the test. A cattle operation selling into beef markets qualifies. A wheat farmer selling grain qualifies. A backyard gardener or someone keeping horses for trail riding does not.

The Kansas Department of Revenue reads “farming and ranching” broadly enough to include feedlots, farm work for hire, nurseries, Christmas tree farming, and aquaculture.² If your use is recreational or personal, using the certificate exposes you to the unpaid tax plus a 10% penalty and interest.³

Filling Out the Form

Open the fillable PDF or print a blank copy. At the top, enter the seller’s name and full address, then your own. Below that, write a specific description of what you’re buying. “Replacement hydraulic cylinder for John Deere combine” is the kind of detail that survives an audit. “Farm parts” is not.¹

In Part A, check every box that fits the purchase. Most purchases fit only one, but some items land in more than one category. If you check the fencing box, complete Part B with the city, state, zip, and county of the land, plus the landowner or operator’s name, and check the certification box. If you’re buying a work-site utility vehicle, complete Part C: confirm the five vehicle specifications, pick the type of agricultural activity, and describe how you’ll use it.

Sign and date the form. Your signature certifies that everything on it is accurate and that the items will be used for exempt agricultural purposes. The ST-28F does not ask for a Kansas tax registration number, an EIN, or a Social Security number.

Which Box to Check in Part A

Part A lists six exemption categories. Pick the one that describes how you’ll use the item.

Farm Machinery, Equipment, Parts, and Repair Labor

Purchase, lease, or rental of farm or aquaculture machinery and equipment used exclusively in production, along with repair and replacement parts and the labor to install them.⁴ Precision farming equipment qualifies, including GPS systems, yield monitors, soil-testing sensors, and the mounting hardware and wiring.²

Consumed in Production

Property used up in the production process. This is where insecticides, herbicides, fungicides, fumigants, germicides, and pesticides used on crops for resale fit. Antibiotics, biologicals, pharmaceuticals, and vitamins fed to or injected into livestock raised for sale belong here too. Off-road diesel, oil, and oil additives consumed by farm machinery, and motor fuels used in plowing, disking, irrigating, planting, cultivating, and harvesting, are also in this category.¹

Ingredient or Component Part

Items that become part of the finished product you’ll sell: seeds, seedlings, and fertilizer for crops grown for resale, and feed for animals whose primary purpose is producing food, dairy, fiber, or fur for sale.⁴

Propane for Agricultural Use

Propane used to heat barns or sheds housing livestock or equipment, brooder and farrowing houses, nurseries, and irrigation equipment, and propane fueling tractors, combines, and other implements.⁴

Soil Erosion Prevention

Seeds, tree seedlings, fertilizers, insecticides, herbicides, germicides, pesticides, fungicides, and related services bought specifically to produce plants that prevent soil erosion on agricultural land.²

Agricultural Fencing

Tangible personal property and services used to construct, reconstruct, repair, or replace fencing that encloses land in agricultural use. Complete Part B when you check this box.¹

Purchases the Certificate Does Not Cover

Some items look agricultural but stay taxable. The form itself flags several.

Passenger vehicles, trucks, truck tractors, trailers, semitrailers, and pole trailers tagged for road or highway use. Farm trailers are the exception.²
ATVs, along with fuel and oil for them.¹
Insecticides for a home garden and antibiotics or vitamins for pets or pleasure animals.¹
Gasoline, diesel, and oil for any passenger vehicle or highway-tagged vehicle, even one driven on the farm.¹
Materials for barns, sheds, and other permanent structures. Those become real property, which the agricultural exemptions for tangible personal property don’t reach.⁴

A work-site utility vehicle can qualify, but only if it meets all five specifications in Part C: at least 48 inches wide, more than 800 pounds unladen with fuel, four or more non-highway tires, bench or bucket seating, and a bed or cargo box. Any recreational use, including hunting, makes the whole purchase taxable.¹

Giving the Form to Your Vendor

Hand the completed ST-28F to the seller at or before the time of purchase. The seller keeps it as proof that tax was not collected, which protects them from liability if the Department audits their records.⁵

You can use the form as a blanket certificate. If you buy regularly from the same equipment dealer or ag supplier, one completed ST-28F covers your qualifying purchases from that vendor going forward. It stays valid as long as no more than 12 months pass between purchases. If a year lapses, provide a fresh one.⁶

Utilities Use a Different Form

The ST-28F does not exempt electricity, gas, or water. For those, file Form ST-28B with your utility company for each meter you want covered.⁷ Electricity and gas used directly in production are exempt from state sales tax but still subject to local sales tax. Water delivered to agricultural premises is exempt from local sales tax as well.

One important limit: electricity and gas used to light, heat, cool, clean, or maintain buildings, offices, warehouses, and general business facilities are fully taxable, even on a farm. The exemption reaches production consumption, not the office or shop. You calculate the exempt percentage on a worksheet and give it to the utility. If that percentage changes, file a revised ST-28B right away.⁷

Out-of-State Purchases

Buying from a vendor in another state shifts the tax rather than eliminating it. If the item would have been taxable in Kansas, you owe Kansas compensating use tax on it. The same agricultural exemptions apply to use tax, so an item that qualifies under the ST-28F is exempt from use tax as well. Provide your exemption documentation to the out-of-state seller rather than assuming they’ll waive tax without it.⁴

Records and Audit Risk

Keep exemption certificates and other sales tax records for the current business year and at least three prior years. Sellers keep their copies for the same period.⁵

If an audit shows the certificate was used for items that weren’t actually used in agricultural production, the state assesses the unpaid tax plus a 10% penalty if it isn’t paid within six months of the original due date, along with interest.³ The most common triggers are claiming the exemption for items with obvious personal or recreational uses (fuel for a highway-tagged truck, chemicals for a home garden, an ATV used for hunting) and vague descriptions that don’t tie the purchase to a specific agricultural use. A description with enough detail to connect the item to how it’s used is the cheapest audit defense you have.

1
Kansas Department of Revenue. Kansas ST-28F Agricultural Exemption Certificate
2
Kansas Office of Revisor of Statutes. Kansas Code 79-3606 – Exempt Sales
3
Kansas Department of Revenue. Penalty and Interest
4
Kansas Department of Revenue. Pub. 1550 Business Taxes for Agricultural Industries
5
Kansas Department of Revenue. Kansas Sales and Use Tax Exemption Certificates
6
Kansas Department of Revenue. Kansas Exemption Certificates Booklet
7
Kansas Department of Revenue. Statement for Sales Tax Exemption on Electricity, Gas, or Water Furnished Through One Meter