The Prompt Pay glitch affected digital money transfers, the association said in a statement.
Some bank customers were unable to transfer money digitally or their transactions were delayed.
Transfers can be made through other channels, such as ATMs and bank counters, the association said.
“For any inter-bank money transfers from 2pm on July 1 that fail to reach the intended accounts, the destination banks involved will put the money in the accounts by 7pm of July 2,” the association said.
Thakorn Piyapan, president of TMB Thanachart Bank, said the Interbank Transaction Management and Exchange (ITMX) system malfunctioned.
The system, operated by National ITMX Co Ltd, serves as the main infrastructure for digital money transfers between Thai banks.
Temporary collapses of the digital banking system are not rare in Thailand, but their number has declined significantly. Four system collapses were reported in the first quarter of this year, down 76% from the 17 in the last quarter of 2022.
Two of the four system collapses involved the Thai Commercial Bank’s mobile banking system, and one each for Krungthai and Bangkok Bank. The collapses earlier this year lasted only an hour or two.