Im 20 male and British. I want to visit my Thai girlfriend for a little under 90 days and wondering about my options.

I was thinking about a tourist 60 day visa with 30 day extention but not sure about it, how likley is it that I wont be able to get an extention and then be stuck for 30 days without a visa till date of my return flight.

I don't have the answer to this, HOWEVER, your question implies another related question, which I would like to add.

If you get a 60 day tourist visa, and your roundtrip air ticket has you coming back in 90 days, you don't really have a visa that covers you for the entirety of your stay. So I wonder if AIRLINES might not let you board if your visa does not cover your whole intended stay.

This must be a pretty common thing for people to do (buy a 90 day return with intention of extending). so hopefully, the experiences are out there on this board.

There is of course the matter of the Thai officials looking at your air ticket when entering Thailand, but that rarely occurs, and you could always say you will be applying for an extension.

You shouldn't have any problem getting a 30 day visa extension in Thailand. Be neat, tidy and polite when you apply. Once you have a Tourist Visa in your passport, the airline is off the hook. Don't worry. Enjoy your stay. .

If you get a 60 day tourist visa, and your roundtrip air ticket has you coming back in 90 days, you don't really have a visa that covers you for the entirety of your stay. So I wonder if AIRLINES might not let you board if your visa does not cover your whole intended stay.

This happened to me on departure from sydney once. The check in customer service officer said "Oh you are going for 4 Months but you don't have a visa for 4 Months". I said to her I do this almost every year, when I get there I stay 3 weeks them I'm going to Cambodia for a visit. After being there I get another 30 days at the border on return. I just tell them "I won't be staying in Thailand that long I will be travelling out of there a fair bit and then eventually flying back home from there." They then realize I know what I'm talking about and let me go. On the Thai arrival side I just say I'm staying only 3 weeks. In your case you say I'm only coming for 60 days, they stamp your tourist visa then you just get a 30 days extension at the immigration office for 1900 baht when that runs out. In 13 years of travelling to Thailand I have never been asked for my return ticket in Thailand.

I forgot to mention, be sure to put only 60 days on you TM card (arrival card) too. Some Immigration Officers are not that bright and if you put 90 days they will probably think you have the wrong visa and give you a hard time.