Area Code +81-503-(3970000...3979999) 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 : 3970000 Subscriber Number To : 3979999 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 : NTT Communications 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-(3960000...3969999) next › : +81-503-(3980000...3989999) Dialling Instructions For trunk calls: 0 503 3970000 (Trunk Code + National Destination Code + Subscriber Number) For international calls: 010 81 503 3970000 (International Prefix + International Dailing Code +National Destination Code + Subscriber Number) Telephone Number List 3970000 ~ 3979999 (Count: 10,000) Example: +81-503-3970000 / 01081-503-3970000 (0503-3970000 / 0-503-3970000) +81-503-3970001 / 01081-503-3970001 (0503-3970001 / 0-503-3970001) +81-503-3970002 / 01081-503-3970002 (0503-3970002 / 0-503-3970002) +81-503-3970003 / 01081-503-3970003 (0503-3970003 / 0-503-3970003) +81-503-3970004 / 01081-503-3970004 (0503-3970004 / 0-503-3970004) ...+81-503-xxxxxxx / 01081-503-xxxxxxx (0503-xxxxxxx / 0-503-xxxxxxx) ...+81-503-3979995 / 01081-503-3979995 (0503-3979995 / 0-503-3979995) +81-503-3979996 / 01081-503-3979996 (0503-3979996 / 0-503-3979996) +81-503-3979997 / 01081-503-3979997 (0503-3979997 / 0-503-3979997) +81-503-3979998 / 01081-503-3979998 (0503-3979998 / 0-503-3979998) +81-503-3979999 / 01081-503-3979999 (0503-3979999 / 0-503-3979999)