What are the current TM30 filing requirements for expats in Thailand after domestic travel?

Bottom line...

Ask your local Thai Immigration office for their TM30 filing requirements.

Sadly for you, the correct answer is to GO to or CALL your immigration office and see what their policy is 🙁

OR

if you have registered with the online system just re-file when ever you come back

What we end up seeing IS

With OVER 80 immigration offices in the country, it's hit or miss as far as what your office really wants you to do.

SOME offices say, once you file a TM30 at your primary address (the address you use for the 90 day reporting and your yearly extensions) you DO NOT need to re-file a new TM30 when you come back from domestic or international travel

BUT

SOME offices say, once you file a TM30 at your primary address (the address you use for the 90 day reporting and your yearly extensions) you DO NOT need to re-file a new TM30 when you come back from domestic BUT you must do it when you return from international travel

AND (sadly)

SOME offices say, you must file a new TM30 when you come back to your primary address whether you travel domestically OR internationally.

It's a total crap shoot..

This is exactly why I urge everyone to make a log in on the online web portal for TM30 or the mobile application (Section 38) and you can file a TM30 on yourself as often as you want to 😛

Definitely register when you arrive, whether or not you need to re-register when returning from domestic travel is up to the local immigration office, contact them and enquire about their policy.