Apologies if this is a simplistic and/or stupid question. 

 

I will enter Thailand on a non-O visa (based on marriage) which I hope to convert into a 12 month extension of stay (undecided whether to go down the marriage or retirement route).

 

Can I enter Thailand without showing a return/ onward air ticket? 

 

Thanks for your help.

Yes. 

You have a visa. Onward flight will not be required for boarding flight or at passport control entering Thailand. 

Before you come, don't forget to apply for the Thailand Pass first.

I would go thru the 1 year marriage extension instead of retirement, that way you don't have tie up your money in the bank. Unless your country's embassy still issues income verification letter.

3 hours ago, dsj said:

I would go thru the 1 year marriage extension instead of retirement, that way you don't have tie up your money in the bank. Unless your country's embassy still issues income verification letter.

Still 400,000 baht in the bank is a lot better than tieing up 800,000 like I have to do! The UK, U.S., AUS and a few others will no longer issue pension income affidavits. 

Thanks to all for the replies