More than 1 million taxpayers who have yet to submit personal income tax forms for 2020 face a deadline of June 30 to file or they face a fine, says Revenue Department director-general Ekniti Nitithanprapas.
He said 9.6 million people have filed their tax returns as of June 24.
June 30 is the last day for such form submission.
The department estimates 11 million people will submit personal income tax forms this year.
Those who fail to submit on time are expected to pay interest to the department at a rate of 1.5% per month for any tax they owe.
Mr Ekniti said for personal income tax, the department has already returned 90% or around 30 billion baht in claimed tax refunds.
The department also sent around 100,000 notification letters to people and companies informing them they failed to report all income sources to the department.
He said this does not mean the department wants to squeeze money out of them, but rather it wants to ensure fair treatment for all taxpayers.
Though the country is struggling with the pandemic, some businesses have still been profitable, said Mr Ekniti.
He said the department has refunded corporate income tax totalling 24 billion baht at present.