Every year you are supposed to pay the "registration fee" about B100(road tax?) , it used to be extra 20B if you were late , now it is pro-rata. The fee if it not paid for 4 years, the registration expires and the book cannot be renewed without re-registering the bike, I didn't want to go thru this hassle. Insurance is paid now before the rego can be renewed and you need to show the receipt. Vehicle inspection paper is needed every year if the bike is over 5 years old by the green book, usually about 60B.This includes the pencil tracing of the frame and engine numbers on paper tape. You can request a new book if it faulty or full, they don't like to give it.
If someone knows different please let me know, this is how Nakhon Ratchasima main motor transport office has been working.