As cited in a previous post, when trying to implement a geographic reclassification of patents applicants and inventors, NUTS classification provides a hierarchical system that lists, for EU, 97 regions at NUTS 1, 271 regions at NUTS 2 and 1303 regions at NUTS 3.
One road may be to use OECD REGPAT database, that covers patent applications filed to the EPO and PCT patents at international phase. Data mainly derives from PATSTAT [this means, if you use the same ediction of your patstat, you may link it via person_id]. The regional allocation is based on the latest Nomenclature of Territorial Units for Statistics (NUTS), 2006 for European regions, and on Territorial Level 3 for other countries; datasets are available for download to researchers: by sending an e-mail to sti.contact@oecd.org. Further methodological information are available on the OECD web site at http://www.oecd.org/sti/ipr-statistics.
In order to make a home-made linkage to NUTS3 may also be useful the link between postcodes and NUTS codes, that is freely available for following 20 countries at this eurostat web page:
http://epp.eurostat.ec.europa.eu/portal/page/portal/nuts_nomenclature/correspondence_tables/postcodes_and_nuts
