Thanks for the reply. I am reading on the Thai immigration site that you can only get a 30 day extension based on an existing visa and not on the visa exemption system (they don't make it easy!). Do you know if that's definitely the case? Let's just say it is possible to do that extension. Do you mean that if you had, for example , evidence of a flight to say Singapore, 25 days after arriving in Thailand, that would be sufficient to satisfy your long haul carrier and they'll issue your boarding pass, even though they'll know you have a return ticket with them 36 days later? Hope that makes sense!!