I've successfully applied for my first extension of stay based upon retirement on December 12, 2018. My next 90-day report is due on December 26, 2018.

 

On the official immigration website I found the following note:

...

"5. The first application for extension of stay by the foreigner is equivalent to the notification of staying in the Kingdom over 90 days."

...

https://www.immigration.go.th/content/sv_90day

 

My questions:
1. As I understand the note, I don't have to submit a 90-day notification in this case. Is that correct?
2. Does this apply only to the very first extension of stay, or also for the future subsequent yearly extensions?

You do not need to make a 90 Report until 90 past Dec 12. Only the first extension application counts as a 90 day report. 

 

12 minutes ago, NanYar said:

1. As I understand the note, I don't have to submit a 90-day notification in this case. Is that correct?

Yes. Your 90 day report is 90 days from the day you applied. If you applied on December 12th your report is due on March 11th.

 

12 minutes ago, NanYar said:

2. Does this apply only to the very first extension of stay, or also for the future subsequent yearly extensions?

Just the very first extension.