Indicators based on patents provide a good measure of the innovative performance and technology outputs of countries. However, because of legal rules imposed by the patent application process, information on patents is generally publicly disclosed after 18 months. Patent indicators are consequently faced with a timeliness issue, which can extend to more than five years depending on the computational method used to develop indicators. This study aims at designing simple but robust methods that would enable to "nowcast" patent indicators - forecast the present (or the recent past) - in order to mitigate the timeliness issue. The nowcasting exercise is conducted here on two separate sets of patent indicators: the number of patents applied to the European Patent Office (EPO) and the number of Triadic Patent Families (patents taken at the EPO, the Japan Patent Office (JPO) and the United States Patent and Trademarks Office (USPTO)). Portion of patent filings at the EPO were made under the Patent Cooperation Treaty (PCT). The nowcasting method developed in the present document is based on estimates of the transfer rate of patents filed under PCT into the EPO regional phase, given that information on PCT patents at international phase is disclosed before reaching the regional/national phase. This method provides robust estimates up to year t-2 (instead of year t-4), even though patenting activity of small patenting countries or emerging economies are difficult to predict, in terms of both level and growth...