Trademarks designed by yourself can be bought and sold. Required documents and materials:

1. "Trademark Agency Power of Attorney": If you entrust a trademark agency to act as an agent, you must provide a power of attorney stamped with the seal of the assignee. If transferees outside the mainland want to apply for trademark transfer in China, they must entrust a trademark agency to do so.

2. "Application Form for Transfer of Registered Trademark": If you entrust an agency to apply for trademark transfer, it will be prepared by the agency and stamped or signed by both the transferor and the transferee.

3. Copies of the transferee’s business license or certification documents of public institutions, associations and other organizations with legal person status. If the transferee is outside the mainland, such documents are not required.