Australian visitors to Thailand can get a free Visa on Arrival for up to 30 days if entering by aircraft or for 15 days if entering overland. This waiver only applies to those with a confirmed onward ticket and at least 6 months passport validity. For more than 30 days, you can apply for a visa in person or by mail to the Thai Embassy in your country. The type of visa will be issued in accordance with the applicant’s purpose of visit. Normally it takes around 3 days to process applications for visas