The vietnamese callsign numbers are determined by the location of the station. Hereunder is a list of those zones and the name of the areas and provinces they are allocated to. These numbers are valid for either 3Wn or XVn prefixes.

1. (and also zone 9) North around Ha Noi :
   Ha Noi, Cao Bang, Bac Can, Lang Son, Thai Nguyen, Bac Giang, Bac Ninh, Vinh Phuc, Hoa Binh, Ha Nam, Ninh Binh.
2. South around Ho Chi Minh City :
   Ho Chi Minh City, Binh Duong, Binh Phuoc, Tay Ninh, Dong Nai, Ba Ria – Vung Tau, Long An, Tien Giang, BenTre, Con Dao island.
3. Upper Central Viet-Nam :
   Da Nang, Quang Tri, Thua Thien – Hue, Quang Nam, Quang Ngai, BinhDinh, Gia Lai, KonTum.
4. Mekong Delta :
   Can Tho, Hau Giang, Vinh Long, Tra Vinh, Dong Thap, Soc Trang, An Giang, Kien Giang, Bac Lieu, Ca Mau, Phu Quoc island.
5. Upper North costal area :
   Hai Phong, Quang Ninh, Hai Duong, Hung Yen, Thai Binh, Nam Dinh.
6. Lower North costal area :
   Nghe An, Thanh Hoa, Ha Tinh, QuangBinh.
7. Lower Central Viet-Nam :
   Khanh Hoa, Lam Dong, Dac Nong, Dac Lac, Phu Yen, Ninh Thuan, Binh Thuan.
8. Inner North Viet-Nam :
   Phu Tho, Son La, Dien Bien, Lai Chau, Lao Cai, Yen Bai, Ha Giang, Tuyen Quang.
9. North around Ha Noi :
   see zone 1.