I have had 400K seeded in my BKK bank investment account for over a year. Last extension to satisfy financials I used the combination method but for simplicity am switching to having the full 800K seeded before my next extension end of March. I have seen various comments about a bank guarantee letter here. Is this a new variation or addition to the bank letter showing accounts balances dated the same day as the application for extension?
TLDR : Answer Summary
The necessity of a bank guarantee letter for a visa extension in Thailand varies by immigration office. In Bangkok, the bank letter can be dated up to 7 days before the application, but the bank book must be updated on the day of the application to reflect the current balance. It's advisable to check with the specific immigration office for their requirements.