Your Section 15 Declaration of Incontestability allows you to request the highest status of trademark protection under federal law. Once your Section 15 Declaration is approved the USPTO, you are protected against many legal challenges that people or businesses might raise to contest your right to your trademark.
If your trademark certificate states that it is on the Principal Register, you have continuously used the mark in commerce for 5 consecutive years since its registration, and no successful challenge has been mounted against your ownership of the trademark or against the mark itself (and no proceeding involving these rights is currently pending) you may file a Declaration of Incontestability.
With incontestable status, you are protected from challenges that your trademark is:
(1) not inherently distinctive and lacks secondary meaning;
(2) confusingly similar to a trademark that someone else began using prior to the owner's registration; and
(3) simply functional.
To file this form, additional one-time filing fees apply.
Because a Section 15 Declaration may be filed after 5 years of continuous use, the holder of a trademark's registration may choose to file a combined Section 8 Declaration of Use/Section 15 Declaration of Incontestability. You must qualify under each section independently to file the combined form.