Vietcombank sold the dollar at VND25,400, up 0.12% from Thursday.
The greenback held firm at VND25,360 on the black market.
The State Bank of Vietnam hiked its reference rate by 0.06% to VND24,213.
Since the beginning of the year, the dollar has increased by 4.01% against the dong.
Globally, the dollar was headed for its third weekly gain in a row on Friday, helped by a dovish European Central Bank and strong U.S. data that is pushing out expectations for how fast U.S. rates can fall, particularly if Donald Trump wins the presidency, Reuters reported.
The U.S. dollar index hit a 2-1/2 month high of 103.87 and is up nearly 0.8% for the week thus far.
The euro is down almost 1% for the week so far, has fallen through its 200-day moving average, and at $1.0837 in Asia trade is parked near a 2-1/2 month low.
On a rolling basis, the dollar's 3.1% three-week gain on the euro is the sharpest rally since the middle of 2022, and it has forged to the strong side of 150 yen for the first time since early August.
The greenback pared some of those gains and last bought 149.93 yen on Friday.
Sterling regained the $1.30 level overnight and held above that level on Friday, but is also headed for a weekly loss after a bigger-than-expected drop in British inflation raised bets the Bank of England might cut interest rates twice before the end of the year.
The onshore yuan ticked 0.06% higher to 7.1199 per dollar, while its offshore counterpart rose 0.12% to 7.1282.