A trademark is a symbol, device or name used in conjunction with a service. Trademarks provide companies a way to indicate the source of their goods and services. A trademark owner has rights to the mark and he or she can prevent others from using said mark due to the confusion that using the same mark may have. Now, trademarks do not stop another company from selling the same goods or the same services. It simply stops that company from using the trademarked name.
Once a person claims a mark, he or she can use the TM symbol to designate the trademark. According to the United States Patent and Trademark Office, even if the trademark registration expires or ends up canceled, the person still has common law rights to the mark. If your trademark expires and another person picks it up, you can usually challenge his or her usage. In determining who had the trademark first, a judge may look at the person who has seniority as the one who has the right to the trademark.
If a trademark goes unused for a specific amount of time, then the product may be abandoned. Once legally abandoned, then another company may adopt the trademark. Trademarks may last for ten-year periods. On the fifth or sixth year, an owner may have need to become familiar with the Declaration of Use. In the last couple of years, you will have to fill out an Application for Renewal.
None of the above information is legal advice. Instead, this is all educational information about expired trademarks.