I believe this commission was for service for inviting guest to use our hotel service. The supplier is UK resident which was conducting service outside Thailand where the DTA between TH and UK state UK has the right to tax this income given that no PE was existed in TH for conducting the service. There should be no TH withholding tax. Self-assessment VAT PP36 may not be required upon the RD’s ruling re offshore traveling agent service.
If the fact was not as I understand, please let me know for amendment of this advice.