The registration of a patent is granted for 20 years as from the date of application. Nevertheless, in order to maintain the registration of a patent of invention, an annuity fee must be paid.
It is important to clarify that the annuity fees are only applicable for patent of inventions which registrations have already granted by the Patent Office.
The due date for the payment is the last day of the month in which the patent application was filed. The legal provisions provide a grace period of six months with an extra-charge of approximately 40% in the official fees.
In case the annuity fees are not paid within the legal terms above mentioned, the Patent Office will declare lapse the patent registration.