Unfair Sales Act

​ Wis.Stat​s s. 100.30​, The Unfair Sales Act and Wis. Adm. Code CH. ATCP 105, Sales Below Cost

Commonly referred to as the "Minimum Markup Law," the Unfair Sales Act prohibits selling items of merchandise below cost. The law states that "the practice of selling…below cost to attract patronage is a form of deceptive advertising and an unfair method of competition in commerce…" Specifically, the law defines cost as:​

  • For all merchandise except alcoholic beverages, tobacco products, and motor vehicle fuel, cost to either wholesalers or retailers is defined as invoice cost or replacement cost, whichever is lower, less all trade discounts, plus any excise taxes and any cost incurred for transportation and any other charges not otherwise included in the invoice cost or replacement cost of the merchandise.

  • For alcohol and tobacco products the definition of cost also includes a 3% cost of doing business markup for wholesalers and a 6% cost of doing business markup for retailers. Cost for wholesalers who operate retail outlets or retailers who purchase directly from the manufacturer includes a 9.18% markup (3% plus 6% compounded).

  • For motor vehicle fuel, the definition of "cost" relies on either the "average posted terminal price" or invoice cost (whichever is greater) plus a cost of doing business markup. Use our Motor Vehicle Fuel Cost Calculator.

  • Penalties for violating the Unfair Sales Act may include a civil forfeiture of $50 to $500 for the first violation and $200 to $2500 for each subsequent violation. Sellers of motor vehicle fuel and/or tobacco products may file a private cause of action to seek damages if they are injured by a competitor's price.

  • Exceptions to the law are made to allow for matching a competitor's price, clearance and final liquidation sales, sales of damaged merchandise and perishables, contracted governmental institution sales and for merchandise sold to charitable or relief agencies.

The Unfair Sales Act applies only to the sale of goods; services are not covered.​

Additional fuel price regulations: Wis.Stats. s. 100.18(8), Fraudulent R​eprese​ntation​

  • At each retail place of business, a price has to be posted in a conspicuous place, most accessible to the public at his or her place of business and on every pump.

  • Once a price has been posted it must remain in effect for at least 24 hours.

  • It is considered deceptive advertising to advertise a sale price for retail less than the price posted on each pump


For further information please contact the Trade Practices staff at (608) 224-4925 or (608) 224-4989.