What should I know about TM30 reporting and annual extension procedures for a non-O retirement visa in Bangkok?

TM30 showing your registered as staying at an address served by Bangkok Immigrations, you should also do your 90 day reporting here at that address (if possible) rather than move just before your extension is due.

In Bangkok you can apply for a new extension when you have 45 days or less left on your current stamp. You need to have the year print out of the detail transaction report, the standard bank letter and update your bank book the date you apply for the extension, TM30, lease, land lord thai i/d maybe the house book copy. Remember if you used banked money method you needed to have kept the 800K baht in the account for 3 months after the extension was granted last year and then the balance couldn't go below 400K the rest of the year until you get it back to 800K baht a minimum of 2 months before you apply for the next yearly extension

This is a generic list of what's required at most offices. It is NOT office specific so I'd suggest you slog on out to Chaengwattana and get the hand out listing the requirements for a yearly extension based on retirement.