If a brand owner fails to adequately protect and enforce its mark, rights in the mark may be weakened or even lost if the mark becomes generic or otherwise loses its capacity to function as a source identifier. Proper enforcement is a multi-faceted undertaking that includes:

For information on ways trademark rights may be lost, see Practice Note, Loss of Trademark Rights.

A key component of enforcement is monitoring the marketplace for infringements or misuses of the trademark owner's mark. While there are a variety of commercial monitoring services available, the most effective monitoring is often by the trademark owner's employees. For example, sales and marketing personnel typically have daily interaction with the marketplace and are often able to readily identify suspected infringements or misuses. Therefore, it can be helpful if the company has internal trademark use guidelines that set out procedures for reporting suspected infringements or misuse (see Standard Document, Trademark Use and Protection Guidelines (Internal Distribution)).

While some infringements may be identified in the marketplace, others may only be discovered when another entity files a trademark application for a potentially infringing mark. Various commercial watch services are available that issue notifications when someone applies to register a mark similar to the trademark owner's mark. Timely identification of problematic applications is critical because it may be possible to raise an objection and settle the matter before the applicant for the infringing mark expends significant resources to develop and use the mark. This is particularly true with intent-to-use applications, where the applicant has likely not begun using the mark in commerce.

Sometimes the nature and extent of the infringing activity is obvious from readily accessible information (for example, the infringer's website). However, the full extent of the infringer's activity is often not easy to discern. In these cases, a trademark owner should consider engaging an experienced trademark investigator to obtain relevant information, including:

The results of the investigation may dictate a particular course of action, or may suggest taking no action at all.

For a discussion of trademark investigations (in the trademark searching and clearance context), see Practice Note, Trademark Searching and Clearance: Investigations of Potentially Conflicting Marks.

It often makes sense for the trademark owner to send a cease and desist letter to the suspected infringer before taking formal legal action. It sometimes may be required, for example under the terms of an agreement. For more information on factors to consider in determining whether to send a cease and desist letter, see Practice Note, Trademark Litigation: Pre-suit Considerations: Assess Whether Sending a Cease and Desist Letter is Required or Advisable.

For a sample cease and desist letter, see Standard Document, Cease and Desist Letter: Trademark Infringement.

Where the infringement is minor or more like a misuse, trademark owner's counsel should consider carefully the appropriate tone of any cease and desist letter and whether an alternative approach, such as a phone call, may be more appropriate. An over-aggressive letter may have negative consequences for the brand owner. The recipient of the letter may post it online, or publicize it in some other manner, in an attempt to generate support from the public and media. This can lead to undesirable negative publicity for the brand owner, including being labeled a "trademark bully," a term increasingly used in the media to describe overzealous trademark owners.

Sometimes a trademark owner may need to initiate formal legal proceedings to protect its brand, for example where an infringer refuses to comply with a cease and desist letter. Proceedings may include: