As long as you apply for a one-year extension based on the same reason as the current one, your next extension will be added to the current extension, which means it will be 10 August 2025 - 9 August 2026, regardless of how early you apply. You don't lose any day to apply early, no worries.

@Vin ********

, as I stated, my comment is for OP, not for others

@Simon ********

, 13th - 16th august in his case

It's "up to 3 days before arrival". You can even submit TDAC in the queue line for passport control at the entry point to Thailand.

You need to wait until the arrival date is selectable on the input calendar on the system. Wait for one month+.

@Vin ********

, my comment is the answer to OP's question.

That you have a TM30 with a Bangkok address doesn't mean you can use any of the immigration offices in Bangkok for your 90-day report.

You said: "you must do the 90 day report in the area in which you either live, or had a TM30 done for you".

That is NOT the case in Bangkok.

Sadly, One Bangkok is not your option if you need to do a 90-day report in person unless your visa/extension is issued there. In Bangkok, the area of responsibility of each office is clearly defined. You must go (or send documents) to the office that issued your visa/extension for your 90-day report in person. (except Non-LA)

@Luna *******

, You definitely want to ask them, bringing your travel information.

Jomtien has a 30-day application window in advance. If I remember correctly, Jomtien can give you extra days in the application window in case you show proof that you will not be in Thailand the whole of the standard 30-day application period. It could be up to 40 days in advance or so.

Usually, a set of one-year transaction history AND a copy of your passbook updated on the day of your application works.

Check with your local immigration office.

To do this, submit a 1-year transaction to your bank, AND update your passbook immediately to avoid a lump sum log after your transaction.

Then, update your passbook on the day of your application to the immigration office.

You might need to deposit/ withdraw a small amount of money to record a clear log on your passbook.

You have to talk with your employer about the procedures/documents to apply for your baby's visa, especially if you are going to do it inside Thailand.

There are companies that don't (or cannot) support employees or family members if they are overstaying or illegally staying in Thailand for their own reasons.

Better be careful to think no problem for children to be overstaying, especially if the main applicant is a Non-B holder.

Technically, yes, it's within 72 hours before arrival, but the system is open for 4 days including "today" as a window for TDAC submission. (day counts at 0:00/ midnight ICT).

Check and try