What are the requirements for a Non O-A visa extension regarding the bank letter at Nonthaburi immigration?

At the Nonthaburi immigration office, it is required that the bank letter for the O A extension must be issued on the same day as the application. This has led to some frustration among expats, as past experiences suggest that other offices may accept letters issued up to seven days prior if the bank book is updated on the application day. Some users note varying experiences about this requirement, indicating that it may be office-specific.