Ideally, you need to have at least 5 years remaining in the validity of your passport. However, in case you have less than 5 years, the Thai Embassy or Immigration Bureau will affix the Thai Elite Visas based on the expiration date stated in your passport. The remaining validity of your visa will then be affixed to your new passport. It is also good to note that you need to have at least 3 blank pages in your passport.