If you live in Bangkok, make an appointment online early morning tomorrow, the next availability is another 30 day from tomorrow. Without appointment, you would be there from dawn til dusk!
FYI, at some immigration offices (BKK is one of), when you go for a yearly extension, a copy of tm.30 doesn't suffice. You still have to bring your rental contract, landlord ID and the house book to immigration.
Agents do for you around 500-1000. Walking in,getting there at 1pm could take you 2-3hours for your turn to be called. By the way, you must have registered the new tm.30 with BKK address before checking in your 90 day.
It's valid up to the expired date of your non-0 stamp. For example your non- 0 stamp from airport/ land border/ visa changing section at immigration is good until 15 Nov 2024 and your first retirement based on that non-o will be up to 15 Nov 2025
I have an experience that if you have the extension from other province, Bangkok immigration office will not accept the tm.30 with new Bangkok address that is filed online. You or your landlord or your agent must file the tm.30 for you in person at CW for the first time . After that you can continue your 90 day online in Bangkok.
You are correct. They now need not only the most recent tm 30 but also the completed set of rental contract, landlord's ID and landlord's house book or land ownership certificate ( Cha-nod.) This is new. Sometime last month, they needed just a tm.30 because in order to get a tm 30 you must have submitted those papers already. So basically you prepare the identical set twice now, one for tm 30 the other for yearly renewal. Noted that with or without agents assistance, the landlord paper set is always required.
The officers usually charge the agent 1000-1500 B for the late 90 day check in, no reciept. So it's normal for them to add an extra 1000 for themselves. Their service is that you don't have to go to immigration and your passport won't be stamped as having failed the 90 day report
When you transfer the stamps onto your new passport, the officer would handwrite down your previous passport number on your passport page. That would be a reference.