I got my Thai teacher to help me do the filing online, it would have been difficult without her help, but once she did help me, it was easy. I was totally honest with my filing as it did not result in too much to pay relative to how much I feel I benefit from being here, I also switched to an LTR visa this year, which means going forwards I don't pay tax on my worldwide income. I reviewed my credit card statements to get everything I bought in Thailand on it and you can get a statement from your Thai bank for interest and withholding tax. I did not supply any bank or credit statements as supporting information however, as you say, there is no place on online filing I could see where I could upload. I just know that should I be investigated, I am squeaky clean. I have no comments on those that say they won't file, I totally get that point of view also. For me, I value being able to stay here long term and paying a small amount of tax correctly this year and having no fear of any false statements come back to bite me in the future is worth it to me.