Vietcombank sold the dollar at VND24,415, down 0.16% from Thursday.
The State Bank of Vietnam kept its reference rate unchanged at VND23,972.
The dollar was stable at VND24,600 on the black market.
It has increased against the dong by 2.89% since the beginning of the year.
Globally, the yen was on track for its best week against the dollar in four months on Friday on the prospect of a narrowing U.S.-Japan rate differential, with bets that the Federal Reserve is done raising rates leaving the greenback headed for a weekly loss, Reuters reported.
Market pricing shows just a 0.3% chance of another rate hike in December, as compared to a roughly 15% chance a week ago, with a 35% chance that the U.S. central bank could begin easing monetary conditions as early as next March, according to the CME FedWatch tool.
That's led to a decline in U.S. Treasury yields alongside a fall in the dollar, which was on track to lose nearly 0.6% on the yen for the week, its worst weekly performance since July.