The all-sky Planck catalog of 1,227 clusters and cluster candidates (PSZ1) derived from Sunyaev-Zeldovich (SZ) effect detections using the first 15.5 months of Planck satellite observations included 683 so-called previously known clusters. PSZ1 was first published in March 2013 (Planck Collaboration 2013 (2013yCat.8091....0P, and 2014A&A...571A..29P). This HEASARC table contains an updated version of the PSZ1 catalog, version 2.1 (10-02-2015) according to the CDS documentation, reporting the further confirmation of 86 Planck-discovered clusters. In total, the PSZ1 now contains 947 confirmed clusters, of which 214 were confirmed as newly discovered clusters through follow-up observations undertaken by the Planck Collaboration. The updated PSZ1 contains redshifts for 913 systems, of which 736 (~80.6%) are spectroscopic, and associated mass estimates derived from the Y_z mass proxy. A new SZ quality flag is also provided for the remaining 280 candidates. This flag was derived from a novel artificial neural-network classification of the SZ signal. Based on this assessment, the purity of the updated PSZ1 catalogue is estimated to be 94%. This table was originally ingested by the HEASARC in May 2013. An updated version (2.1) was ingested by the HEASARC in October 2015 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/581/A14">CDS Catalog J/A+A/581/A14</a> files psz1v2_1.dat and notes.dat. This is a service provided by NASA HEASARC .