number belongs to the subscriber number. The international call prefix depends on the country from which you are calling, for example, 00 for most European countries and 011 from North America. In 2001-2002, Greece moved to a closed ten-digit numbering scheme in two stages, with the result that subscribers' numbers changed twice. For example, before the change, a number in Athens would have been dialed as follows: In 2001, a '0' was added after the area code, which was incorporated into the subscriber's number: Finally, in 2002, the leading '0' was changed to a '2' (for geographic numbers) : For mobile phone numbers, the leading '0' was changed to a '6'. Note that because of number portability, for both geographical and non-geographical (mobile, toll-free, premium rate) numbers, one cannot be sure about the operator that a number belongs to. All geographical codes (21x, 231x) end in a number from 0 to 6 (210 or 212 for Athens, 2310 or 2312 for Thessaloniki). Numbers whose code ends in "0" are or were originally operated by OTE. The same applies to mobile phones: All mobile codes (69x) end in 0,3,4,5,7,8 or 9 (690, 698). Mobile code "696" is assigned to OTE pagers. Numbers starting with 690 and 693 were originally assigned to WIND, with 694 and 695 to Vodafone, with 697 and 698 to Cosmote and with 699 to Q-Telecom until 2007 when it merged with WIND. Zone 21: Greater Athens Metropolitan Area 21 - (0-9)XXXXXXX Athens-Piraeus-Elefsina area Zone 22: Central Greece and the Aegean Islands 222x - Evia 2221 - Chalkida City 2222 - Kymi 2223 - Aliveri 2224 - Karystos 2226 - Aidipsos 2227 - Mantoudi 2228 - Psachna 2229 - Eretria 223x - Evrytania and Phthiotis 2231 - Lamia 2232 - Domokos 2233 - Atalanta 2234 - Amfikleia 2235 - Kamena Vourla 2236 - Spercheiada, Makrakomi 2237 - Karpenisi 2238 - Stylida 2239 - not used 224x - Dodecanese 2241 - Rhodes, Rhodes City 2242 - Kos and Nisyros islands 2243 - Kalymnos, Astypalaia 2244 - Rhodes Island, Archangelos Area 2245 - Karpathos and Kasos islands 2246 - Rhodes Island, Salakos Area - Chalki, Kastellorizo, Symi and Tilos islands 2247 - Agathonisi, Leros, Leipsoi and Patmos islands 2248 and 2249 - not used 225x - Lesbos, Lemnos 2251 - Lesbos, Mytilini Area 2252 - Lesbos, Agiasos Area 2253 - Lesbos, Kalloni Area 2254 - Lemnos, Agios Efstratios 2255 through