According to article 80 of Decision 486 of the Andean Community of Nations, to keep a patent in force or to maintain a pending patent application, as the case may be, an annual fee must be paid, determined by the national office of each country.
The deadline for payment of each annual fee shall be the last day of the month of presentation of the invoice. Two or more annual fees may be paid in advance.
Annual fees shall be paid within a grace period of six months after the starting date of the corresponding annual period, together with the prescribed surcharge. The patent or pending application shall remain in full force during the grace period.
Failure to pay an annual fee produces the expiry of the patent or patent application.