The Seoul city government is offering a cash reward of 500,000 won ($A450) to anyone informing the authorities about taxi drivers who rip off foreign tourists.
City officials said on Thursday that the move was an attempt to curb a practise that was "still rampant" despite previous crackdown efforts.
Government official Kim Su-Jeong said that foreigners ripped off by taxi drivers could claim the reward themselves by dialling an English-language hotline and reporting the driver.
"Many taxi drivers unduly demand extra charges or do not use the taxi fare calculators in order to exact unfair charges from foreigners," Kim said.
Seoul has around 400 specialised cabs, known as "international taxis," which are equipped with interpretation services and whose drivers can speak English and Japanese.