The check is at the airport or border checkpoint on arrival, not halfway your holiday when you decide that you actually live in Thailand. Wake up in the real world to avoid nightmares.
People need to do some research before they plan to go on holiday. I did not know and I did not check are nowhere in the world legitime answers for your behavior.
1. a Single Entry Non Immigrant O visa (populair called retirement visa)
2. a Multiple Entry Non Immigrant O visa (populair called retirement visa)
3. a Multiple Entry Non Immigrant O-A visa (populair called retirement visa)
4, a Multiple Entry Non Immigrant O-X visa (populair called retirement visa)
5, the LTR Visa (populair called retirement visa)
Or get into Thailand and apply as Tod describes for the Non Immigrant O visa (populair called retirement visa)
And later for the 1 year Extension of Stay (populair called retirement visa)
And when you have this 1 year Extension of Stay you apply for a single or multiple Re-Entry Permit to be free to travel and keeping your period of stay alive.
Benefit of the Non Immigrant O-A visa is that you get stamped in for 1 year of stay. IF you go abroad just before the visa expires and come back before the valid until date you still get a new 1 year of stay, so you can almost stay 2 years inside Thailand using this visa.
And as you are already almost 2 years in Thailand you can use the proof that you made deposits for at least 12 months before application date of minimum 65.000 Thb into a Thai bank account in your name only.
The first year must be 800.000 Thb in a Thai bank is for people who only are in Thailand for 90 days or do a conversion of their tourist status and can not provice 1 year statements.
Which means you do not have to try several times to fill in the online application. You get directly an answer that it is recieved and you wait for the result, if denied you visit Immigration, you do not try again with same details.
Assuming you are not visiting other countries for just a few minutes or hours, apply in the last to visit country at a Thai Embassy for the Single Entry Tourist Visa and safe all the hassle.
So get to Thailand without visa and get 30 days Visa Exempt.
Fly to other countries, apply there for the visa and on return get 60 days based on the visa.
Before travel apply for the Non Immigrant O visa based on being over 50 years of age (retirement) using the on-line application system:
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He will get 90 days of stay when he arrives and show this visa from the Immigration booth at the airport.
Than he can contact the Canadian Embassy, get a affidavit of income and use that to apply after 60 days but before the 90 days ends for the 1 year Extension of Stay based on being over 50 years of age.