Is there a grace period for using a bank letter for a one-year Non-O-A visa extension in Thailand?

The acceptable period for a bank letter when applying for a one-year Non-O-A visa extension varies by immigration office in Thailand. Some offices, like those in Bangkok and Chiang Mai, may accept letters that are up to 7 days old, while others require the letter to be issued on the same day as the application. It is recommended to check directly with the relevant immigration office for their specific requirements regarding the bank letter and to ensure that the passbook is updated on the day of the application.