If a trademark has no legal effect, then generally there is no way to use it, otherwise it will be illegal. A registered trademark is valid for 10 years. If a registered trademark needs to be continued to be used after it expires, an application for registration renewal should be made within 6 months before expiration. If you fail to apply during this period, there is still a 6-month extension period. If an application has not been filed within the extension period, the Trademark Office will cancel it after the expiration of the extension period. The "Trademark Law of the People's Republic of China" stipulates that upon expiration of the statutory period, if the party concerned does not apply for review of the Trademark Office's decision to declare the registered trademark invalid or the Trademark Review and Adjudication Board's review decision, maintain the registered trademark or declare the registered trademark invalid. If a lawsuit is filed in the People's Court, the Trademark Office's decision or the Trademark Review and Adjudication Board's review decision or ruling shall take effect. A registered trademark declared invalid in accordance with the provisions of Articles 44 and 45 of this Law shall be announced by the Trademark Office, and the exclusive right to use the registered trademark shall be deemed to have ceased to exist from the beginning. Decisions or rulings declaring the registered trademark invalid, judgments, rulings, and mediation documents on trademark infringement cases made and executed by the People's Court before the invalidation, and decisions on handling trademark infringement cases made and executed by the industrial and commercial administration departments, as well as The executed trademark transfer or licensing contract does not have retroactive effect. However, compensation shall be provided for losses caused to others due to the bad faith of the trademark registrant. Article 47 of the Trademark Law of the People's Republic of China declares a registered trademark invalid in accordance with the provisions of Articles 44 and 45 of this Law, and shall be announced by the Trademark Office, and the exclusive right to use the registered trademark shall be deemed to be invalid. It does not exist from the beginning. Decisions or rulings declaring the registered trademark invalid, judgments, rulings, and mediation documents on trademark infringement cases made and executed by the People's Court before the invalidation, and decisions on handling trademark infringement cases made and executed by the industrial and commercial administration departments, as well as The executed trademark transfer or licensing contract does not have retroactive effect. However, compensation shall be provided for losses caused to others due to the bad faith of the trademark registrant. If the trademark infringement compensation, trademark transfer fees, and trademark usage fees are not returned in accordance with the provisions of the preceding paragraph, which obviously violates the principle of fairness, all or part of the compensation shall be returned.