If you entrust an agency to apply for a patent, you must first sign a confidentiality agreement and then sign a contract. The contract stipulates the payment method. Generally, you need to pay first, and then the agency will draft it. After submission, it will be issued by the State Intellectual Property Office. The official fee must be paid for the acceptance notice and payment notice, and the balance of the agency fee will be paid if there is any. The patent then enters the review period.