Since about 2021, From a legal point of view, if you are returning to your permantly registered property (as per tm30) within the registered stay period, [checkout date future or null], there is no need to re-register, this applies to both internal and external travel of Thailand. This should be fine for 90 day reporting purposes eg on-line. However, if visiting imigration many offices will insist on a new TM30 (especially when the check-in date is prior to your visa extention or arrival in country date. Problems can arise with internal travel, where your last hotel/etc don't fill in the checkout date of their tm30, and this becomes your address on record. I travel a fair bit within Thailand to hotels and never redo my tm30 and dont have a 90 day reporting problem, but i always register a new tm30 for my extension of stay done at CW.
The training video online has been available for a couple of years, so its probably just a temporary glitch with the site. You view the video and answer some observation questions to prove you watched it (during & at end) anytime prior to the visit to dlt. When you completed the viewing you save and print the qr code to take with you.
I think you'll find the under consideration period runs to the 'later of' 30 days or visa expiraration date. I use CW which is 20 days, and in 12 years never received a considerstion date end less than my previous extension date.
i'd get a new accountant, that is the only change that has been made, and the cause of all the discussions around taxation in the last 18 months. If you have money that would be assesable if you bring it into Thailand in the year it was gained, it will remain assesable if you delay bringing it until following tax year. (It doesn't become non-assesable now, like it used to).
banks in Thailand have a standard process to issue both a statement from the day of request back (3, 6 or 12 months) plus a letter to the chief immigration officer verifying your a customer and you've maintained the qualifying funds. These are stamped by the bank and are the required documents by immigration to confirm funds held in a Thai bank where this is a prerequisite for an extension of stay. These cost a couple of hundred baht, and must not be more than 7 days old when presenting them at IM. So if you are using Thai funds to support your status rather than foreign funds, then its only to be expected that immigration will require the usual documentation they require for all other extensions.
that unfortunatly is the rule change, the pre 2024 date for non assesable is now static, (it used to basically increase each year). So only monies that were accumalated prior to 2024, can be treated as non taxable. Monies accumalated in
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and remitted the following year maybe taxable at the end of the year based on their source.