the extension period of trademark renewal right can be about 18 months. Where a registered trademark needs to be used continuously after its expiration, the trademark registrant shall go through the renewal procedures in accordance with the regulations within 12 months before the expiration; If it cannot be handled within this period, a six-month extension period can be given. Legal basis: Article 4 of the Trademark Law of the People's Republic of China. If a registered trademark needs to be used continuously after its expiration, the trademark registrant shall go through the renewal procedures in accordance with the regulations within 12 months before the expiration. If it fails to be handled during this period, a six-month extension period may be granted. The validity period of each renewal registration is ten years, counting from the day after the last expiration of the trademark. If the renewal formalities are not completed at the expiration of the period, the registered trademark shall be cancelled. The Trademark Office shall announce the renewed registered trademark.