Vietcombank sold the dollar at VND23,710, up 0.04% from Thursday.
Eximbank maintained it at VND23,620, and Techcombank kept it stable at VND23,710.
The State Bank of Vietnam increased its reference rate by 0.05% to VND23,711.
The dollar was sold at VND23,575 on the black market, down 0.02%.
It has fallen against the dong by 0.08% since the beginning of the year.
Also on Friday the yen languished near a 15-year low against the euro and around a seven-month trough against the dollar, ahead of a closely-watched policy decision by the Bank of Japan, where it is set to stay ultra-dovish in the face of its hawkish peers, Reuters reported.
The Japanese yen was last just over 0.1% higher at 140.09 per dollar, having bottomed at 141.50 per dollar in the previous session, its lowest since November.
The euro was poised for its best week since November after a hawkish European Central Bank (ECB) signalled further rate hikes to come, after raising borrowing costs to a 22-year high overnight.
That and a run of soft U.S. economic data saw the dollar fall broadly as traders scaled back their bets on how high U.S. interest rates would need to rise.