I travelled to Chiang Mai last year on Qantas. I planned to stay 6 weeks, which was the time period of my outbound and return flights.
I emailed a visa agent in CM before my travel who gave free advice. She said I was fine to get a 30 day visa on arrival, and I could renew it for another 30 days at immigration in CM. This saved me the "hassle" (so I thought) of working with the Thai Consulate to have a visa period sufficient to cover my travel dates.
Qantas wouldn't let me on the outbound flight. Luckily (in this instance) the outbound flight was delayed 4 hours. I called the Thai Consulate, who emailed me a message saying they were ok for me to travel (I admit their email was a bit vague). Qantas still wouldn't let me on the flight even with the email.
My choices were limited: bail on the trip, at least for those dates, and likely lose all hotel deposits, or change the return flight to an earlier flight. Luckily there were earlier flights available. Immigration in BKK did not even ask about my return flight. Once in Thailand I moved my return flight back to my original date. Of course both changes incurred change fees.
Lesson learned: don't just consider what Thai immigration will do, but what the airline will do.
(As an aside, Qantas customer service is abominable. Literally 8 hours or longer on hold to speak to customer service - not an exaggeration although it may have improved since Alan Joyce got the boot; this question isn't covered by their website FAQ's; they don't provide email support; they don't answer questions in their FB group. Hopefully your airline makes it easier to get an answer to this scenario, but I would think the safest option is for your visa validity to completely cover the time period for your outbound and return flights. Otherwise make SURE you know what your airline will do when you're trying to check in.)
First thanks for all your help (and everyone else). I really appreciate it.
I haven't created a login - perhaps that makes a difference? I've explained the steps I took in my previous replies to you and Andi. I'm using the browser on my computer. I can't find the steps to take to get to the Non-O visa. Screenshots don't help; I need the *exact* steps on the e-visa website or the URL after you've navigated to the Non-O visa.
OK thanks. If anyone can find the *URL* for the Non-O visa on the e-visa website please post it. Otherwise I will contact the Thai Embassy for further guidance.