Maintenance fees or renewal fees are fees paid to maintain a granted patent in force. Some patent laws require the payment of maintenance fees for pending patent applications. Not all patent laws require the payment of maintenance fees and different laws provide different regulations concerning not only the amount payable but also the regularity of the payments. In countries where maintenance fees are to be paid annually, they are sometimes called patent annuities. Rationale Research is indicating that renewal fees can be used to improve the innovation incentives generated by patent rights. International treaties Paris Convention Article 5bis of the Paris Convention requires that parties to the convention should provide a six-month grace period for paying maintenance fees: (1) A period of grace of not less than six months shall be allowed for the payment of the fees prescribed for the maintenance of industrial property rights, subject, if the domestic legislation so provides, to the payment of a surcharge. (2) The countries of the Union shall have the right to provide for the restoration of patents which have lapsed by reason of non–payment of fees. Patent Cooperation Treaty International patent applications filed under the Patent Cooperation Treaty are not subject to the payment of maintenance fees. However, maintenance fees may fall due to designated/elected national and regional offices. If renewal fees have become due by the time the national phase starts, they must be paid before the expiration of the time limit applicable for entering the national phase. National and regional legislations Canada In Canada, maintenance fees for a patent application, or a patent issued from the application, are due on each anniversary of the filing date of the application, beginning on the second anniversary. The amount due each year escalates during the life of the patent or patent application. If the maintenance fee is not paid (by the applicant or agent of record) by the due date with respect to a patent application, the application is deemed abandoned. The abandoned application may be reinstated within 12 months of the date of abandonment, by filing a request for reinstatement with payment of the maintenance fee that is due and the reinstatement fee. The maintenance fee for a patent may be paid within a one-year grace period after the due date, with the payment of a late fee. If the required fee has not been paid when the grace period expires,