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What the Magnuson-Moss Act Does Not Allow
There are three prohibitions under the Magnuson-Moss Act. They involve implied warranties, so-called "tie-in sales" provisions, and deceptive or misleading warranty terms.
Disclaimer or Modification of Implied Warranties
The Act prohibits anyone who offers a written warranty from disclaiming or modifying implied warranties. This means that no matter how broad or narrow your written warranty is, your customers always will receive the basic protection of the implied warranty of merchantability. This is explained in Understanding Warranties.
There is one permissible modification of implied warranties, however. If you offer a "limited" written warranty, the law allows you to include a provision that restricts the duration of implied warranties to the duration of your limited warranty. For example, if you offer a two-year limited warranty, you can limit implied warranties to two years. However, if you offer a "full" written warranty, you cannot limit the duration of implied warranties. This matter is explained in Titling Written Warranties as "Full" or "Limited".
If you sell a consumer product with a written warranty from the product manufacturer, but you do not warrant the product in writing, you can disclaim your implied warranties. (These are the implied warranties under which the seller, not the manufacturer, would otherwise be responsible.) But, regardless of whether you warrant the products you sell, as a seller, you must give your customers copies of any written warranties from product manufacturers.
"Tie-In Sales" Provisions
Generally, tie-in sales provisions are not allowed. Such a provision would require a purchaser of the warranted product to buy an item or service from a particular company to use with the warranted product in order to be eligible to receive a remedy under the warranty. The following are examples of prohibited tie-in sales provisions.
In order to keep your new Plenum Brand Vacuum Cleaner warranty in effect, you must use genuine Plenum Brand Filter Bags. Failure to have scheduled maintenance performed, at your expense, by the Great American Maintenance Company, Inc., voids this warranty.
While you cannot use a tie-in sales provision, your warranty need not cover use of replacement parts, repairs, or maintenance that is inappropriate for your product. The following is an example of a permissible provision that excludes coverage of such things.
While necessary maintenance or repairs on your AudioMundo Stereo System can be performed by any company, we recommend that you use only authorized AudioMundo dealers. Improper or incorrectly performed maintenance or repair voids this warranty.
Although tie-in sales provisions generally are not allowed, you can include such a provision in your warranty if you can demonstrate to the satisfaction of the FTC that your product will not work properly without a specified item or service. If you believe that this is the case, you should contact the warranty staff of the FTC's Bureau of Consumer Protection for information on how to apply for a waiver of the tie-in sales prohibition.
Deceptive Warranty Terms
Obviously, warranties must not contain deceptive or misleading terms. You cannot offer a warranty that appears to provide coverage but, in fact, provides none. For example, a warranty covering only "moving parts" on an electronic product that has no moving parts would be deceptive and unlawful. Similarly, a warranty that promised service that the warrantor had no intention of providing or could not provide would be deceptive and unlawful.
A Businessperson's Guide to Federal Warranty Law