Can I apply for a 30-day extension on my Tourist Visa in Chiang Mai online or do I need to go to an Immigration Office?

Do a border run to loas for another 30 days extension

This will help you

You go to the Immigration office where your staying, yes you can apply 2 weeks prior, its added to your 60 days stamp not from the day you apply. Not sure about copies at the office but most do have facilities to do it. You may also need the TM30 some office require some dont.

You could drop in to the immigration office and ask what they want.

Did you actually apply for a visa or just got the visa exempt stamp on arrival, If applying in Bangkok it would make a difference to the office you go to. Chiang Mia probably same office.

At Central Festival Mall the immig office is on the 2nd floor, (supermarket end). They open at 9am but people start queuing 8am.

There are 2 booths where you can take pics and make copies. You can get the TM 7 form there just inside the immig area. Don't forget the TM 30

You should do the preliminary stuff the day before or earlier so you're ready to submit it all 0900am..

Stand in the line at the left, they'll give you a queue no.

Fee B1900.... Not sure about an express fee though

I'm about to apply in 2 or 3 weeks 😂

No you cannot do it online. You need to go to an immigration office.

You do not get to pick and choose your immigration office. You must go to the immigration office that matches the province where you are staying, as that is where your TM30 should be filed. That being said, Chiang Mai does in fact have 2 offices where you can apply for a tourist extension. One is the main office near the airport and I believe the other is at central festival mall.

In Chiang Mai you can apply for an extension 45 days in advance.