Hi! I am a US citizen who received a Visa upon arrival at the Bangkok airport. My dates in Thailand are from Jan 14th, 2016 to February 10th, 2016. I have two questions I would like to ask the experts here:

1. I will be flying from Bangkok to Phuket and from Phuket to Chiang Mai during my stay. Will my visa upon arrival allow me to travel within the country hassle free during my 30 days? At the airports in Phuket and Chiang Mai, will showing them my original stamp be enough to enter?

2. I will be leaving Thailand to head to Australia from January 30th - February 6th. I will fly back into Bangkok from Australia on Feb 6th. I plan on spending my last 4 days (Feb 6th-Feb 10th) in Thailand before flying home. I have my return ticket already purchased. I read that my Visa is on arrival is no longer valid once leaving the country. Will I receive a new one for the 4 days I have left until my return flight home to the USA? I would like to avoid any hassles at the airport and avoid seeming like I'm trying to do a border run. Without a re-entry visa, will I be ok to return to Thailand and spend the last 4 days here before returning to the USA once back from Australia?

Thank you very much in advance for your help!

You do not have a Visa on arrival.

You have a Visa Exempt Entry.

When you return from Australia you will be given another Visa Exempt Entry of 30 days.

Flying within the country, you will be arriving at domestic arrivals so they won't even look.

Edited January 15, 201610 yr by Eclipse

You have a 30 day visa exempt entry, not a visa on arrival.

1. You can travel freely within Thailand. You do not pass through immigration for internal flights and the airline will only want to see your passport as ID.
2. You do not need a re-entry permit. You will receive a new 30 day visa exempt entry when you return from AUS.

Edited January 15, 201610 yr by elviajero

You got a 30 day visa exempt entry when you entered the country.

1. You only need passport for identification purposes at the airports. They will only look at the photo page.

2. You will get another 30 day entry when you return to the country without a problem.

Thank you very much for your replies! Also, thank for the clarification on my Visa. I really appreciate it My questions have been answered.