Expiry date (patent)
The date when patent protection ends and the technology enters the public domain — usually twenty years from filing.
The expiry date of a patent is the date on which exclusive rights end and the protected technology enters the public domain. For most utility patents the expiry date is twenty years from the filing date, provided that all maintenance fees have been paid on time. Earlier termination can occur if fees are missed, if the patent is abandoned, or if it is revoked in opposition or invalidity proceedings. Supplementary protection certificates can extend protection for pharmaceuticals and plant protection products in some jurisdictions. Knowing the expiry profile of a patent family is essential for product planning, licensing strategy, and renewal decisions.