Area Code +81-603-(3700000...3799999) located in Fixed Mobile Convergence service, more detail is as below. Place International Dialing Code : 81 International Prefix : 010 National Prefix : 0 National Destination Code : 603 Subscriber Number From : 3700000 Subscriber Number To : 3799999 National Destination Code Length : 3 Uses National Destination Code : Yes National Significant Number Length : 10 Number Type : M (Mobile, Cellular) 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 : Fixed Mobile Convergence service Timezone : Asia/Tokyo Coordinated Universal Time : +09:00 Daylight Saving Time : No National Significant Number Minimum Length : 10 Latitude : None Longitude : None ‹ previous : +81-603-(3600000...3699999) next › : +81-603-(3800000...3899999) Dialling Instructions For trunk calls: 0 603 3700000 (Trunk Code + National Destination Code + Subscriber Number) For international calls: 010 81 603 3700000 (International Prefix + International Dailing Code +National Destination Code + Subscriber Number) Telephone Number List 3700000 ~ 3799999 (Count: 100,000) Example: +81-603-3700000 / 01081-603-3700000 (0603-3700000 / 0-603-3700000) +81-603-3700001 / 01081-603-3700001 (0603-3700001 / 0-603-3700001) +81-603-3700002 / 01081-603-3700002 (0603-3700002 / 0-603-3700002) +81-603-3700003 / 01081-603-3700003 (0603-3700003 / 0-603-3700003) +81-603-3700004 / 01081-603-3700004 (0603-3700004 / 0-603-3700004) ...+81-603-xxxxxxx / 01081-603-xxxxxxx (0603-xxxxxxx / 0-603-xxxxxxx) ...+81-603-3799995 / 01081-603-3799995 (0603-3799995 / 0-603-3799995) +81-603-3799996 / 01081-603-3799996 (0603-3799996 / 0-603-3799996) +81-603-3799997 / 01081-603-3799997 (0603-3799997 / 0-603-3799997) +81-603-3799998 / 01081-603-3799998 (0603-3799998 / 0-603-3799998) +81-603-3799999 / 01081-603-3799999 (0603-3799999 / 0-603-3799999)