The greenback fell by 0.23% to VND25,730 at unofficial exchange points.
Vietcombank kept its rate unchanged at VND25,463.
The State Bank of Vietnam maintained its reference rate at VND24,251.
Globally the yen jumped to a six-week high against the dollar on Friday after faster-than-expected inflation in Tokyo supported bets for a Bank of Japan interest rate hike next month, Reuters reported.
The dollar was last down 1.27% at 149.62 yen, and earlier dipped to 149.47 yen, the lowest since Oct. 21. It is set for a 3.38% weekly loss against the Japanese currency, the largest since July.
The dollar index fell 0.31% to 105.74, after earlier reaching 105.61, the lowest since Nov. 12.