How many days before expiration should I extend my 30-day visa exempt stamp at the Chaengwattana immigration office, and do I need a TM 30?

To extend a 30-day visa exempt stamp in Bangkok, you should apply for an extension when you have 45 days or less remaining on your current stamp. Instead of Chaengwattana, you will need to go to the immigration office at IT Square Laksi. It is advised to avoid going on Mondays and Fridays due to crowdedness. Additionally, a printed copy of the TM 30 may sometimes be requested.