Those who employ foreigners as tour guides will also face action, the ministry said, reports the Bangkok Post.
Labour Minister Trinuch Thienthong said that with the high season approaching, with many visitors travelling in tour groups, some operators are resorting to hiring foreign tour guides, which violates labour laws.
A tour guide is one of 27 protected occupations that are off-limits to foreigners. As such, foreigners cannot obtain work permits for this job, and those with valid permits for other occupations cannot legally act as guides.
Ms Trinuch said the government is focused on boosting the economy and promoting tourism to bring revenue into the country, so hiring foreign guides not only breaks the law but also takes jobs away from Thai citizens.
According to the minister, if foreigners are found working without a permit or working beyond the scope of their permit, they could be subject to a fine of B5,000 to B50,000, deportation and a ban from applying for another work permit for two years. Employers who hire unlicensed foreign workers face fines ranging from B10,000 to B100,000 per worker.