1. First, decide which patent to buy. Is it authorized? You can go to the National Intellectual Property Network to find those published patents, or you can go to those patent transfer networks, such as Oudun Patent Exchange Network, which contains many patents in various fields.

Secondly, you can negotiate the specific purchase with the patentee yourself or through an agency. Including: understanding of patented technology, price negotiation.

3. Agree on the specific transfer right, whether to transfer the whole patent right or exclusive license.

Finally, you can go to China National Intellectual Property Administration to handle the transfer formalities yourself or find a patent agency. It is suggested to find a patent agency here, because they know more about the specific matters.

Buying a patent is to transfer the right of that patent to your own name, which is basically the same as buying a trademark. The specific payment method should be negotiated by both parties, but usually the patent purchase is a one-time payment, and the subsequent products have nothing to do with the patentee. If it is a patent license, it is more related to the production volume of the product, because more license fees can be charged, which depends on your ideas and interests.