What documents do I need for my first 90-day reporting in Chiang Mai besides my passport?

For your first 90-day reporting in Chiang Mai, besides your passport, you should also prepare your TM30 form. Although it is not usually requested, having it on hand is advisable, so it's recommended to staple it into your passport to avoid losing it. Additionally, ensure that you have filled out the TM47 form. You can also complete this process online after your initial notification is done in person, ideally doing it one week in advance to allow for any potential issues.