The driver, Tran Anh Tuan, also had his driving license revoked for two months, Cong An Nhan Dan reported.
The move came a week after the Thai female tourist complained on social media, saying she had booked a car for VND1.5 million (US$61) for traveling from her downtown hotel to Linh Ung Pagoda on Son Tra Peninsula, Ba Na Hills and Hoi An city.
The driver later asked her to pay VND3.8 million, 2.5 times against the negotiated fare.
She also uploaded a photo of the driver’s car with a yellow license plate, with many Vietnamese netizens calling for an investigation to avoid hurting Da Nang’s tourism reputation.
Authorities confirmed the Thai tourist’s allegations on social media were true.
Da Nang, famous for its long, sandy beaches, is a popular destination for tourists from Thailand but taxi scams have been frequently reported.
Earlier this year a man in Da Nang was fined VND11 million for impersonating a taxi driver and charging a South Korean tourist 10 times the usual fare.