Can I apply for a 30-day extension of stay after receiving a visa exemption stamp in Thailand?

Yes, you can apply for a 30-day extension of stay at a Thai immigration office since you've recently entered Thailand on a visa-exempt entry. The application fee is 1,900 Thai baht, and you can typically apply when you have 30 days or less left on your current stamp, though some offices may allow applications when you have up to 45 days remaining. The extension will be added to your current stamp, commencing on the date you apply for the extension.