What are the requirements for the TM30 form and 90-day reporting for expats in Thailand?

Doing an online 90 day report gets “routed” to the local immigration office that would handle it the same as you did in person. Some offices have different rules and requirements. Some don’t care if you are returning from abroad to your same address, some don’t care if you’ve been out of the province. Some will if you have.

The new 90 day report system ties in with the new TM30 system so you will find that some are approved and some are rejected depending on the policy of the particular office that handles it.

As an example. In Phuket if you’ve had an extension from another province (almost always via an agent) or stayed in a hotel out of province you cannot use the 90 day online system. You must apply in person. I believe this is specific to Phuket so your mileage may differ in your province.

Our address is constant and Jomtien don't expect you to do a tm30 each time you return

The need to file a new TM30 after leaving Thailand and returning is different depending on which immigration office you use.