How do I transfer my Thai visa from an old passport to a new US passport after renewal?

When transferring a Thai visa to a new passport after renewal, it's important to know you cannot transfer the visa directly but rather need to handle your entry stamp. It's recommended to show both your old and new passports at the airport when departing, as this process is usually quick. For more specific cases, such as extended stays or longer visa types, you may need to visit a local Immigration Office with required documents including copies of both passports and potentially a letter from your embassy. Always check for the most current immigration requirements.