People holding more than 100 mobile SIM cards per person, comprising a group with a combined 5.89 million cards, were told to register their identity through their mobile phone operator service centre or app by Feb 14 to avoid the cards being terminated.
According to Pol Gen Nathathorn Prousoontorn, commissioner of the National Broadcasting and Telecommunications Commission (NBTC), there are 7.1 million SIM cards owned by people who each hold more than 100 SIM cards.
Of these cards, only 1.22 million have been registered as of Jan 28.
Recent NBTC measures require holders of more than five mobile SIM cards to register their identities at customer service centres or on mobile operator apps from Jan 16 to ensure the cards are not terminated after the registration deadline.
Under the measures, people who hold 6-100 SIM cards must verify their identity by July 13 this year.
People who hold more than 100 SIM cards must verify their identity by Feb 14.
Pol Gen Nathathorn said there are a total of 10.9 million SIM cards subject to the new regulation, but only 1.28 million cards were registered as of Jan 28.
There are 3.8 million SIM cards owned by people who each hold between 6 and 100 cards, but only 68,414 have been registered for this cohort.
He said if holders of these SIM cards fail to verify their identity by the deadline, they will not be able to make outgoing calls.
Following suspension, the owners will be given another 30 days to register their identities, after which the cards will be permanently terminated, said Pol Gen Nathathorn.
"The SIM cards held by this group are being monitored as they have the potential to use them for fraud," he said.
"That is why the registration period for this group is only 30 days after the regulator's announcement."
The NBTC has issued many measures to eliminate fraud committed through the use of mule SIM cards, especially numbers in the prepaid system with no real user registration or with incorrect or incomplete information.