E-shopping for foreign goods had led to tariff collection worth about Bt5 million every month, he said.
To provide services for taxpayers, the department will send tax bills to their address, so they can make an e-payment transaction with the department and they do not need to visit a Post Office for tax payments.
The department also found many shoppers illegally bought marijuana from the United States after many states legalised consumption of the drug, he said.
He said the department will start to introduce online customs procedure on September 1 to alleviate imports and exports.
Tax evaders will be punished severely if they repeat an offence, he warned.