Area Code +856-21-(830000...839999) located in Vientiane, more detail is as below. Place International Dialing Code : 856 International Prefix : 00 National Prefix : 0 National Destination Code : 21 Subscriber Number From : 830000 Subscriber Number To : 839999 National Destination Code Length : 2 Uses National Destination Code : Yes National Significant Number Length : 8 Number Type : G (Geographic Land Line, Fixed Line) Carrier Name : Laotel Click here to buy Laos Area Code Database Other Information Language Code : lo (Laothian) Country Number : 418 (Laos) Country Code : LA (Laos) City : Vientiane Timezone : Asia/Vientiane Coordinated Universal Time : +07:00 Daylight Saving Time : No National Significant Number Minimum Length : 8 Latitude : 17.9600 Longitude : 102.6100 ‹ previous : +856-21-(810000...819999) next › : +856-31-(210000...219999) Dialling Instructions For trunk calls: 0 21 830000 (Trunk Code + National Destination Code + Subscriber Number) For international calls: 00 856 21 830000 (International Prefix + International Dailing Code +National Destination Code + Subscriber Number) Telephone Number List 830000 ~ 839999 (Count: 10,000) Example: +856-21-830000 / 00856-21-830000 (021-830000 / 0-21-830000) +856-21-830001 / 00856-21-830001 (021-830001 / 0-21-830001) +856-21-830002 / 00856-21-830002 (021-830002 / 0-21-830002) +856-21-830003 / 00856-21-830003 (021-830003 / 0-21-830003) +856-21-830004 / 00856-21-830004 (021-830004 / 0-21-830004) ...+856-21-xxxxxx / 00856-21-xxxxxx (021-xxxxxx / 0-21-xxxxxx) ...+856-21-839995 / 00856-21-839995 (021-839995 / 0-21-839995) +856-21-839996 / 00856-21-839996 (021-839996 / 0-21-839996) +856-21-839997 / 00856-21-839997 (021-839997 / 0-21-839997) +856-21-839998 / 00856-21-839998 (021-839998 / 0-21-839998) +856-21-839999 / 00856-21-839999 (021-839999 / 0-21-839999)