It is not illegal to use a trademark that is not registered, but can you be sure that the trademark is not registered? If someone later registers the trademark and you don't know it, it is illegal for you to still use it. Therefore, it is beneficial and harmless to register your own trademark now. It is not expensive. It costs about 1,600 to find an agency to register one. If no one else has registered it, it can take one year. You cannot apply as an individual, you must apply to the Beijing State Administration for Industry and Commerce through an agency