How long can I apply for a patent for invention after applying for a patent for utility model?

The same invention, invention patent and utility model patent can be applied at the same time, but it must be the same person, and the application for utility model and invention patent must be filed before the publication of utility model patent or at the same time.

It should be noted that the application for a patent for invention must be filed before the publication of the patent for utility model, and the patent for utility model must be abandoned during the examination of the patent for invention, otherwise the patent for invention cannot be authorized.

Applying for a utility model patent and an invention patent at the same time has two advantages:

First, when the invention patent is not authorized, we can rely on the protection of the utility model patent, and then give up the utility model patent when the invention patent is approved;

Second, when applying for an invention patent, you can also add a method invention.