Johnson County overtaxed Walmart and Sam’s Club by millions of dollars by overstating the value of the retailers’ property, the Kansas Board of Tax Appeals found.

The ruling on Friday could be more costly than it appears for the county, because Walmart isn’t the only large retailer that has protested appraised valuations, The Kansas City Star reports. Target and Home Depot are among other big-box retailers challenging Johnson County tax appraisals going back a couple of years.

(Read more: Kansas City Business Journal – The Business Journals)