We arrived Thailand on tourist visa and applied for retirement visa (3 months) that ubojoe suggested, we got that all ok. This runs out 26th March. I believe we can apply for 12 months up to 45 days before. What is ideal time to apply so we dont loose any of the 3 months and what is the latest we should apply

You will not lose any of the 90 days when you apply for the extension of stay. The extension will start from the end of the 90 days.

At many offices the earliest you can apply is 30 days while others allow it up to 45 days. There is no latest date you can apply other than the last day of your 90 days. I suggest doing it no later than 2 weeks before the date your entry ends.

If using the 800k baht in the bank option it will need to be in the bank for 60 days on the date you apply.

Thank you Sir very Kind

Now I understand