The Finance Ministry is assessing consumer demand for the co-payment scheme, with the possibility of launching a third phase of registration if necessary.
"We are not closing in on increasing the number of eligible people by more than 5 million for a third-phase [registration]," said Finance Minister Arkhom Termpittayapaisith.
Mr Arkhom's remarks came after 5 million people registered for the second-phase co-payment scheme within two hours after online registration opened at 6am on Wednesday.
The registration system was overwhelmed and the process of confirming registrants' identity via a one-time password (OTP) crashed for those using DTAC mobile service.
Total Access Communication (DTAC) is the country's third largest mobile operator by subscribers.
#dtac and #คนละครึ่งเฟส2 (second-phase co-payment) were trending hashtags in Thailand on Twitter following DTAC's OTP system failure.
Mr Arkhom said it will take three days from Dec 16 to screen registrants for the second-phase co-payment scheme.
Qualified registrants for the scheme will receive an SMS to confirm their eligibility.
For registrants who have not received their OTPs or receive delayed OTPs after the registration quota was full, the Finance Ministry will look into the issue by assessing the size of this group and how they can take part in the scheme, he said.
A poster advertises the co-payment scheme at a food stall at a rally. VARUTH HIRUNYATHEB
Regarding the crash of the Pao Tang app, used for identification and payment in the scheme, it was attributed to registrants of the first-phase co-payment scheme using the app to confirm the extra 500-baht subsidy for the second phase of the scheme, said Mr Arkhom.
Some people were also using the app to buy items, he said.
Under the co-payment scheme, the government pays for 50% of food, drink and general goods purchases for up to 150 baht per person per day, capped at 3,000 baht per person for a specified duration.
The objective is to stimulate consumer spending in the final quarter after sentiment was gutted by the pandemic.
The first-phase scheme started on Oct 23 and ends on Dec 31. The government allocated 30 billion baht for the first-phase scheme.
The second-phase co-payment scheme covers an additional 5 million people, with the amount of subsidies raised from 3,000 to 3,500 baht per person.
The existing 10 million people who have already registered with the first-phase scheme will be eligible for an additional 500 baht.
The second-phase co-payment scheme will be implemented between January and March 2021.
The scheme also extends the rights of existing registered users to March next year.