There are two types of licenses for providing postal services, i.e. the general license and the special license. The latter one is required when the operator provides services that do not substantially differentiate from the universal postal service. The registration to the Registry of Postal Services is equivalent to the acquisition of General License. Decision on General Licences in its Annex I stipulates that in case the legal person is comprised of foreigners, they need to submit their working permits together with their application [see ΑΠΟΦ 686//2013 (ΑΠΟΦ 686/064 ΦΕΚ Β 1700 2013): Κανονισμός Γενικών Αδειών Παροχής Ταχυδρομικών Υπηρεσιών] For unofficial version see: http://www.taxheaven.gr/laws/law/index/law/419 AND http://www.odigostoupoliti.eu/kanonismos-genikon-adion-parochis-tachidromikon-ipiresion/