Can I extend a 45-day visa exempt entry stamp at Patong immigration or do I need to visit Phuket immigration?

Yes, you can extend a 45-day visa exempt entry stamp at any immigration office in Phuket, including Patong, Blue Tree Water Park, or the main office in Phuket Town. The choice of office is up to you, and it was noted that Blue Tree is typically the least busy option. Also, ensure that you visit before the immigration office closes for the holiday.