What is the renewal fee? When is it required to be paid?

To keep the patent in force, a renewal fee must be paid annually. The first renewal fee is payable for the third year and must be paid before the expiration of the second year from the date of the patent. Suppose the patent has not been granted within two years. In that case, the renewal fees may be accumulated and paid immediately after the patent is granted, or within three months of its recordal in the Register of Patents or within an extended period of 9 months by paying extension fees of six months, from the date of recordal. If the renewal fees are not paid within the prescribed time, the patent will cease to have effect. However, provision to restore the patent is possible provided the application is made within eighteen months from the date of cessation.

The renewal fee is counted from the date of filing the Patent application. Six months' grace time is available with an extension fee for payment of the renewal fee.