Patent rights, once established, are not permanent. The protections they offer must be renewed regularly through the payment of patent annuities, also known as patent renewal fees. If unpaid, the patent lapses.
The intervals at which such payments must be made vary: In numerous jurisdictions, renewals are due annually starting several years from the date of patent filing — for example, one under Chinese law, three for EU member states and Brazil, four in Japan. The U.S. has a more complicated process, requiring renewal payments three, seven and 11 years from the date of filing for utility patents, but no renewals whatsoever for design patents. Most patents have a life expectancy of 20 years in most countries even if renewal payments are properly made; at that point, inventors must file entirely new patents if they aim to keep their IP adequately protected.