You may use the registered trademark symbol ® if your mark is registered, although only in connection with the products or services for which your mark is registered.
You may use the ™ symbol (for trademarks) or the ℠ symbol (for service marks) at any time, whether or not you have filed a trademark application for that mark. These symbols simply put the public on notice that you claim trademark rights in the mark.
The usual best practice is to use the ® or ™ symbol only once per mark per piece of advertising material. That is sufficient to put third parties on notice of your claim of rights in the mark without cluttering up the advertisement.
You may refer to your trademark, service mark, or trademark or service mark registration in textual statements at any time. For example, our company could note that “TM TKO is a registered trademark of TM TKO, LLC.”
If you own a certification mark, that mark is itself a symbol that you have certified a product or service as complying with certain standards. You do not need to add an additional symbol, like ™ or ®. Qualifying product or service providers will have the right to use the certification mark symbol if they meet the standards you set out.
The copyright symbol © is not related to trademarks, other than to the extent an image may both be copyrightable and serve as a trademark. For more on copyrights, please read our guide about the different types of intellectual property.
Remember that trademark rights are territorial – if you own a registration in the US, that does not necessarily give you the right to use the ® symbol on the same product in other countries.
Finally, use errors frequently crop up when a mark is both a company’s main brand and the most prominent part of their company name. When referring to the company, you do not need to (and should not) use either the ™ or ® marking. For example, in the sentence “Google released its third quarter earnings today,” “Google” refers to a company, and is properly used as a noun with no marking. However, in the sentence like “The new Google Translate™ app is amazing,” “Google” is a part of the mark “Google Translate,” which serves as an adjective that indicates the source of the noun “app,” and, if that is the first reference to the mark, the marking symbol would be appropriate. For more information about the relationship between trademarks and business names, please read our guide "How Do Trademark Rights Relate to Business Name Rights?"