Abstract <p>Merging earthquake catalogs is a popular procedure in many studies based on seismicity analysis. This is necessary, in particular, to create a single catalogue for adjacent territories and to enhance the representativeness of catalogs based on data from various regional networks of seismic stations. When merging catalogs, the problem arises of identifying duplicating records related to the same seismic event. A recently developed algorithm for identifying duplicates using a modified nearest-neighbor method has proven its effectiveness in creating merged catalogs of the Russian Arctic. The application of this method involved several stages: preliminary identification of duplicates, determination of metric parameters, determination of the threshold value of the metric, and, ultimately, final identification of duplicates and merging of catalogs. Based on the accumulated experience, a fully automated method for merging earthquake catalogs with duplicate identification and the corresponding software product were developed, which we present in this paper. The input data are the original catalogs, and the user gets a merged catalog cleared of duplicates.</p>