Do I need a re-entry permit for my O-A visa and when does my 90-day reporting start?

@Mehmet ******

just so you understand, you will NOT do a 90 day report this time because you aren't staying here 90 days

that means this statement isn't correct :)

𝟮- 𝗠𝘆 𝘀𝗲𝗰𝗼𝗻𝗱 𝟵𝟬 𝗱𝗮𝘆 𝗿𝗲𝗽𝗼𝗿𝘁 𝗽𝗲𝗿𝗶𝗼𝗱 𝘄𝗶𝗹𝗹 𝘀𝘁𝗮𝗿𝘁 𝘁𝗵𝗲 𝗱𝗮𝘆 𝗜 𝗺𝗮𝗸𝗲 𝗺𝘆 𝗿𝗲-𝗲𝗻𝘁𝗿𝘆 𝘁𝗼 𝗸𝗶𝗻𝗴𝗱𝗼𝗺 𝗮𝗴𝗮𝗶𝗻.

when you come back it will be your FIRST 90 day report, and every time you come back into the country it's the "first" report because the 90 day count down resets when you stamp in

Q.1- I don't need to buy a re entry permit for the first year of this visa?

-> If Non-OA itself is still valid and you have a valid insurance policy valid when you enter Thailand again, you don't need a re-entry permit. You will be stamped in for a shorter period of 365 days or the validity of the insurance policy.

Better bring a copy of the insurance policy in hand when you enter Thailand again, just in case.

2- My second 90 day report period will start the day I make my re-entry to kingdom again.

-> That's correct. Your 90-day count starts when you arrive in Thailand again; the arrival day is day 1.