Looking at renewing my Retirement Visa but have found conflicting reports of the number of months required by Chiang Mai Immigration.  Is it 6 months, 12 or 18 months that you need to have remaining on your Australian Passport before applying.

There is no minimum number of months remaining on your passport's validity to apply for an extension of stay (not a visa) requirement.

But if you apply for it with less than 12 months of validity remaining on it your extension will only be issued to the date it expires.

If your passport had 6 months remaining you would only be given a 6 month extension of stay.

 

Towards the the end of the 6 months, assuming you’ve got a new passport, you would apply for a new 1 year extension.

3 hours ago, Aussie Blue said:

Looking at renewing my Retirement Visa but have found conflicting reports of the number of months required by Chiang Mai Immigration.  Is it 6 months, 12 or 18 months that you need to have remaining on your Australian Passport before applying.

It's an extension of your permission to stay, not a visa. If you have less than a year remaining on your passport, it might be a good idea, if possible, to get a new passport before applying for the extension.  If not, the extension (and re-entry permit if you get one) will only be valid up to the expiration date on your passport and then you would need to apply for another extension after getting a new passport.

6 hours ago, ubonjoe said:

There is no minimum number of months remaining on your passport's validity to apply for an extension of stay (not a visa) requirement.

But if you apply for it with less than 12 months of validity remaining on it your extension will only be issued to the date it expires.

Immigration  In Hat Yai advised me  6 Months Minimum for Extension based on retirement. 

13 minutes ago, digger70 said:

Immigration  In Hat Yai advised me  6 Months Minimum for Extension based on retirement. 

That would be a local policy but it would also be good advice. I would not want to apply for another extension in less than 6 months after applying for one.

Another factor is that 6 months passport validity is required to enter many countries. Many embassies advise that you should renew your passport when you get to 9 months of validity.