The new band, on either side of a value set daily by the central bank within which the dong can move, took effect Monday following rate hikes by the U.S. and other countries.
The SBV also depreciated the dong by VND455 to the dollar to VND24,380.
It said it would continue to closely monitor movements and use policy tools when necessary or intervene in the forex market to stabilize it.
On Monday, the country’s largest lender Vietcombank set its selling rate rate at VND24,440.
The U.S. Dollar Index, which measures the greenback’s strength against six major currencies, firmed at 113.12.