What's the difference between a non immigrant O (retirement) and a non immigrant OA visa? I think you can get the OA only outside Thailand, but are there other important differences? For instance, the O seems to be valid for 90 days and renewed by reporting every 90 days. The OA seems to be valid for a year with multiple entries and can be renewed for a further year, but is there a 90 day reporting requirement? Any advice on the differences between the 2 visas is appreciated.