The National Broadcasting and Telecommunications Commission (NBTC) is calling on all TV platform operators to follow the rule limiting commercials to no more than six minutes an hour.
The limit also covers digital programmes rerun on any TV platform.
On any given day, the average ad airtime stands at about five minutes an hour.
The NBTC's new requirement calls for all TV platform operators to feature no more than six minutes of advertising an hour even if they rerun digital TV programmes on their broadcasting systems apart from programmes required by the must-carry rule.
The announcement was issued after the NBTC passed a resolution on Sept 24 ordering digital TV channel operators to halve the limit of commercials on free TV to a maximum of six minutes an hour or an average of five minutes an hour in one day.
The limit on commercials is aimed at protecting TV audiences from watching too many commercials, in accordance with Section 28 of the Broadcasting Act.
"The NBTC will not let consumers be exploited by broadcasters who run commercials beyond the limit," secretary-general Takorn Tantasith said.
"If anyone finds any TV channels have ads over the limit, please inform the regulator at the call centre."
The NBTC's call centre has a 1200 hotline.
Those violating the TV commercial limit and take advantage of consumers will face an administrative fine of not more than 5 million baht plus a daily fine of 100,000 baht, based on Section 77 of the Frequency Allocation Act.
The daily fine will be collected until the broadcaster stops running commercials above the maximum limit.
In another development, the NBTC agreed in principle to three draft announcements to solve the problem of community radio transmissions disrupting aviation communications.