Tomorrow I'll have to take my wife to a cell phone store to register her SIM card.
For those who did not notice this, all owners of a SIM card that was activated before April 24, 2017 must go to the phone providers store no later than April 24, 2018 and re-register the SIM card (with a profile picture), otherwise the SIM card will be blocked after 15 days.
http://vietnamnews.vn/society/426021/no … rvice.html
It is also advisable to register SIM cards that have not been registered (or have been registered under a unknown name) with your own name.
For example, my first Vietnamese SIM card (Viettel) I bought in the past officially for 250'000 Dong at the airport in HCMC was not registered with my name (you can check this by texting TTTB to the number 1414).