I have one question regarding with holding taxes. What kind of with holding taxes are non resident foreign companies subjected to on the income earned in Thailand. I have been told by some one that offshore companies incorporated in the US (Delaware etc) are subject to 5% with holding tax in Thailand. Is that correct?

The rates of withholding tax vary depending on the type of income. I can think of 5% as applicable to royalty falling under the category of literary work such as use of softwares. Dividend is at 10% and interest is at 15%.

For service fees, it can be exempted if the services cannot be construed as royalty and the corporation does not have a permanent establishment in Thailand per the US/Thailand Double Taxation Agreement.