What should I do if I forget to hand in my paper?

Hand it in as soon as possible.

Within two months after the prescribed time limit, you can pay the restoration fee 1000 yuan for restoration; After more than two months, the patent was completely invalid. The following are the payment times of the patent fee and the application fee: the payment period of the application fee is within two months from the date of filing or 15 days from the date of receiving the acceptance notice. The fees paid at the same time as the application fee also include publication printing fee and application surcharge. Where the priority is claimed, the priority claim fee shall be paid at the same time. Substantive examination fee for an application for a patent for invention: the payment period of the substantive examination fee is within three years from the date of application (if there is a priority requirement, the earliest priority date shall prevail).