Area Code +81-503-(2310000...2319999) located in VoIP, more detail is as below. Place International Dialing Code : 81 International Prefix : 010 National Prefix : 0 National Destination Code : 503 Subscriber Number From : 2310000 Subscriber Number To : 2319999 National Destination Code Length : 3 Uses National Destination Code : Yes National Significant Number Length : 10 Number Type : V (VoIP, Location Independent fixed land line) Carrier Name : KDDI Click here to buy Japan Area Code Database Other Information Language Code : ja (Japanese) Country Number : 392 (Japan) Country Code : JP (Japan) City : VoIP Timezone : Asia/Tokyo Coordinated Universal Time : +09:00 Daylight Saving Time : No National Significant Number Minimum Length : 10 Latitude : None Longitude : None ‹ previous : +81-503-(2300000...2309999) next › : +81-503-(2320000...2329999) Dialling Instructions For trunk calls: 0 503 2310000 (Trunk Code + National Destination Code + Subscriber Number) For international calls: 010 81 503 2310000 (International Prefix + International Dailing Code +National Destination Code + Subscriber Number) Telephone Number List 2310000 ~ 2319999 (Count: 10,000) Example: +81-503-2310000 / 01081-503-2310000 (0503-2310000 / 0-503-2310000) +81-503-2310001 / 01081-503-2310001 (0503-2310001 / 0-503-2310001) +81-503-2310002 / 01081-503-2310002 (0503-2310002 / 0-503-2310002) +81-503-2310003 / 01081-503-2310003 (0503-2310003 / 0-503-2310003) +81-503-2310004 / 01081-503-2310004 (0503-2310004 / 0-503-2310004) ...+81-503-xxxxxxx / 01081-503-xxxxxxx (0503-xxxxxxx / 0-503-xxxxxxx) ...+81-503-2319995 / 01081-503-2319995 (0503-2319995 / 0-503-2319995) +81-503-2319996 / 01081-503-2319996 (0503-2319996 / 0-503-2319996) +81-503-2319997 / 01081-503-2319997 (0503-2319997 / 0-503-2319997) +81-503-2319998 / 01081-503-2319998 (0503-2319998 / 0-503-2319998) +81-503-2319999 / 01081-503-2319999 (0503-2319999 / 0-503-2319999)