Mr Takorn said the businessman, whose name has been withheld, received the bill after he used data roaming services on his smartphone while he was abroad for a month.
He said the NBTC had instructed Total Access Communication (Dtac) and True Move, two of the three major mobile operators in Thailand, to urgently look into the man's data roaming usage. He might have pressed wrong buttons on his phone, or mistakenly tampered with its system. Advanced Info Service (AIS) is the third mobile operator.
"The user complained that he couldn't use his smartphone in a foreign country, and had to restart it many times.
"He wasn't made aware of the charges when his smartphone had a problem, and it's impossible that he could have run up a 14 million baht bill,' Mr Takorn said.
He said the NBTC will on Thursday meet representatives of Google's Play Store, a digital distribution platform for applications for the Android operating system, and mobile operators to discuss plans to limit spending on mobile content and applications to 1,000 baht, and to send short messages to alert mobile customers who install mobile applications for the first time
The move comes after reports of children racking up six-digit bills after playing games on their parents' smartphones.