Regarding the progress of changing area code, phase 1 shall be started from 11^th January 2017 for 13 provinces and cities; phase 2 shall be started from 15^th April 2017 for 23 provinces and cities and phase 3 shall be started from 17^th June 2017 for remaining 23 provinces and cities. The changes shall be within one month for each stage. During that period, subscribers can use both old and new area codes parallel. After March 13^rd 2017 (phase 1), May 14^th 2017 (phase 2) and July 16^th 2017 (phase 3) those provinces shall be used new area code completely. To mitigate connection loss during the changes, each stage shall be carried out in 4 steps including  notified on media, conducted technical measures parallel to dial in 30 days, maintained audio notifications during at least 30 days after the end of the dial in parallel; ended audio nofitications - Calls successful only when users dial the new area code. The changing of the area code is an implementation of the planning steps of telecom inventory, ensuring telecommunications resources are used efficiently

After the implementation, all area codes are all fixed to 2, making room for cell-phone numbers to be shortened from 11 digits to 10 digits, contributing to the limitation of spamming SIM and SMS.

Binh Duong Province shall implement area code changing in the third stage, starting from June 17^th 2017 to July 16^th 2017 after the new area code of 274 shall replace the current 650.

Stages of telephone area code changing

Stage 1 (from February 11^th 2017 to March 12^nd 2017) includes provinces of Son La, Lai Chau, Lao Cai, Dien Bien, Yen Bai, Quang Binh, Quang Tri, Thua Thien Hue, Quang Nam, Da Nang, Thanh Hoa, Nghe An and Ha Tinh.

Stage 2 (from April 15^th 2017 to May 14^th 2017) includes provinces of Quang Ninh, Bac Giang, Lang Son, Cao Bang, Tuyen Quang, Thai Nguyen, Bac Can, Hai Duong, Bac Ninh, Hai Phong, Ha Nam, Thai Binh, Nam Dinh, Ninh Binh, Ca Mau, Bac Lieu, Can Tho, Hau Giang, Tra Vinh, An Giang, Kien Giang and Soc Trang.

Stage 3 (from June 17^th 2017 to July 16^th 2017) includes provinces and cities of Ha Noi, Ho Chi Minh, Dong Nai, Binh Thuan, Ba Ria - Vung Tau, Quang Ngai, Binh Đinh, Phu Yen, Khanh Hoa, Ninh Thuan, Kon Tum, Dak Nong, Dak Lac, Lam Dong, Gia Lai, Vinh Long, Binh Phuoc, Long An, Tien Giang, Binh Duong, Ben Tre, Tay Ninh andDong Thap.

Telephone area codes of Vinh Phuc, Phu Tho, Hoa Binh, and Ha Giang remain unchanged.