China Mobile's second certification needs to provide the company's business license, legal person's ID card, agent's ID card and unit's letter of introduction and other materials, and affix the official seal. These materials are used to prove the legitimacy and identity confirmation of the enterprise, so that China Mobile can carry out the second authentication. Please note that the specific certification process and required materials may be different in different regions and specific situations. For specific requirements, it is suggested to contact the local customer service of China Mobile or go to the local business hall.