Nearly 60,000 migrant workers have had their status rendered as illegal and are no longer allowed to stay in the country after they missed Saturday's deadline for registration under the new labour law.
Authorities say 1,379,252 migrant workers from Myanmar, Cambodia and Laos applied for registration with the ministry's one-stop service (OSS) centres nationwide on the last day of registration.
Of them, 1,320,035 (96%) were able to legally register, according to Labour Minister Adul Sangsingkeo.
The status of the remaining unregistered 59,217 migrant workers has now been rendered illegal as of Sunday.
They now are not permitted to stay in Thailand and must return to their home countries or face legal action, Pol Gen Adul said.
He noted that some of the undocumented migrant workers may already have left ahead of the deadline.
They may return to Thailand to seek re-employment through the formal labour import system under memoranda of understanding Thailand has with its neighbouring countries, the minister said.
The minister also said that a total of 961,946 have completed the processes required to secure work permits which will extend their stay until March 31, 2020.
These processes involve going through nationality verification, receiving identification numbers, passing health exams and obtaining visas.
Pol Gen Adul said there are more than 350,000 migrant workers who have not yet completed these steps.
Of them, 127,429 have obtained visa stamps and have applied for work permits while 190,056 have registered online and 40,604 have submitted registration paperwork with the OSS centres.
These migrant workers are required to finalise the processes at the OSS centres which will reopen on April 23, Pol Gen Adul said.
Those who registered by Saturday's deadline will be allowed to stay until June 30 so they can finalise their work permits.
Pol Gen Adul added that these migrant workers can now have health check-ups at state-run hospitals and apply for visas at all immigration offices without having to wait for the OSS centres to reopen on April 23.
According to the cabinet resolution on Jan 16, about 2 million migrant workers from Myanmar, Laos and Cambodia were temporarily allowed to work in the kingdom until Saturday.
Those migrant workers were required to register under the new labour law by Saturday's deadline so the authorities could consider extending their stay.
Failure to do so will result in a fine of 5,000 to 50,000 baht each for workers and 10,000 to 100,000 per worker for employers.
Repeat offences by employers will result in fines of up to 200,000 baht per worker, a jail term of not more than one year and a three-year ban on being allowed to employ foreigners.
Government spokesman Sansern Kaewkamnerd Sunday said Prime Minister Prayut Chan-o-cha thanks migrant workers and their employers who have complied with the law.
He stressed migrant workers who have failed to follow the law can no longer stay and work in the country.
Violators will face legal action and so will those who employ illegal workers, he said.