Section 15 Declaration of Incontestability
A sworn statement, filed by the owner of a mark registered on the Principal Register, claiming "incontestable" rights in the mark for the goods/services specified. An "incontestable" registration is conclusive evidence of the validity of the registered mark, of the registration of the mark, of the owner's ownership of the mark and of the owner's exclusive right to use the mark with the goods/services. The claim of incontestability is subject to certain limited exceptions set forth in SS15 and 33(b) of the Trademark Act, 15 U.S.C. SS1065 and 1115(b). 15 U.S.C. S1065.
Filing a Section 15 Declaration is optional. However, there are certain rules governing when one may be filed. A S15 Affidavit may not be filed until the mark has been in continuous use in commerce for at least five consecutive years subsequent to the date of registration for marks registered under the Act of 1946 (and subsequent to the date of publication under S12(c) of the Trademark Act, 15 U.S.C. S1062(c), for marks registered under the Acts of 1905 and 1881 for which the benefits of the Act of 1946 have been claimed). The S15 Affidavit must be executed and filed within one year following a 5-year period of continuous use of the mark in commerce.
Marks registered on the Supplemental Register are not eligible for claims of incontestable rights under S15.
Source: U.S. Patent and Trademark Office.