The Federal Trade Commission announced Tuesday that it had sent letters to six major companies, informing them that the "warranty void if removed" stickers on specified parts aren't just meaningless, but also illegal.

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Under the 1975 Magnuson-Moss Warranty Act, companies cannot place repair limits on warranties "unless warrantors provide the parts or services for free or receive a waiver from the FTC."

“Provisions that tie warranty coverage to the use of particular products or services harm both consumers who pay more for them as well as the small businesses who offer competing products and services,” Thomas B. Pahl, ating director of the FTC’s Bureau of Consumer Protection, said.

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The major companies it contacted market and sell cellular devices, automobiles or video gaming systems in the United States, products that commonly feature the warning stickers. In fact, both the Sony Playstation 4 and Xbox One video game consoles come with the stickers.

Here are some examples of service claims that violate the 1975 law, according to the FTC:

  • The use of [company name] parts is required to keep your … manufacturer's warranties and any extended warranties intact.
  • This warranty shall not apply if this product … is used with products not sold or licensed by [company name].
  • This warranty does not apply if this product … has had the warranty seal on the [product] altered, defaced, or removed.

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The agency said it has asked the contacted companies to review their warranty notices and ensure that they don’t "state or imply that warranty coverage is conditioned on the use of specific parts of services."

Officials will then review the companies' websites after 30 days, and inform them that "failure to correct any potential violations may result in law enforcement action."

Read the full FTC announcement at ftc.gov.