What are the legal consequences of declaring a patent invalid?

Legal analysis: 1. An invalid patent right shall be deemed as nonexistent from the beginning. It can be seen that the invalidation of patent right can be traced back to the time when the patentee enjoys the patent right.

2. The decision to declare the patent right invalid has no retrospective effect on the judgments and rulings of patent infringement made and executed by the people's court before the patent right was declared invalid, the decisions on handling patent infringement disputes that have been performed or executed, and the patent licensing and patent transfer contracts that have been performed. However, if the patentee's malice causes losses to others, it shall make compensation.

Legal basis: Article 3 of the Civil Law of People's Republic of China (PRC) The personal rights, property rights and other legitimate rights and interests of civil subjects are protected by law, and no organization or individual may infringe upon them.