Not exactly true. As individuals, I could sell you something and you could pay me in crypto. There is no law against that.
What is prohibited in Thailand is the creation of an actual payment gateway that uses crypto and facilitates e-commerce payments for goods and services.
But anyone doing e-commerce, whether their customers are only in Thailand or from elsewhere, can use a crypto payment gateway based outside of Thailand.
notes:
Since April 1, 2022, the Securities and Exchange Commission (SEC) has prohibited digital asset business operators—such as crypto exchanges and wallet providers—from facilitating or promoting the use of digital assets for purchasing goods or services. This means these businesses cannot offer payment services using cryptocurrencies or develop systems that support such transactions.
However, this regulation does not extend to private individuals. Private transactions between individuals, where cryptocurrencies are used as a medium of exchange, are not explicitly banned. Yet, the Bank of Thailand (BOT) discourages the general public from using digital assets for payments due to concerns about financial stability and potential risks like money laundering.
In summary, while it's not illegal for private individuals to use cryptocurrencies for payments in Thailand, such activities are discouraged by financial authorities.