The Department of Land Transport has suspended a tuk-tuk driver's licence and fined him 2,000 baht for overcharging Japanese tourists.
He was also fined 500 baht for failing to wear a proper uniform.
The 29-year-old driver, from Roi Et province, was fined on Tuesday, suspended for 90 days and ordered to attend a three-hour training session in drivers' manners.
This followed a complaint by a Japanese tourist that he and three other drivers demanded they pay 1,500 baht each for a 5-kilometre trip from Sukhumvit soi 18 to Thaniya Plaza on Monday night.
Finally they reportedly settled the fare at 2,000 baht.