Annual Maintenance of a Patent
If you want to keep the protection of your invention you should pay the official annual fees. If the invention continues to be commercially interesting, you may keep the patent alive for 20 years.
Payment of Annual Fee
To maintain your patent you need to pay the official annual fee to Rospatent.
If the fee is not paid, the patent becomes invalid and any person can start exploiting the invention that previously was protected by the patent.
However, there is a grace period, and the patent can be renewed within three years period of non-payment of annual fee.
Annual Maintenance Cost