I suggest that you go to the office where you will extend and get their requirement list first then work off that. Also, get any of the forms you need to fill out at the same time.
Wife's 90 report was done in person today which means it was not done when the extension was processed. I suspect that was due to the change of reason in the extension.
Only took an hour and a couple photo copies, better than a 2,000 THB fine.
Apologies Todd, I neglected to mention that yesterday we submitted a 90 day report online in accordance with the previous receipt. Received notification today that is was rejected, verbiage in the rejection email is - "This online application can be submitted 15 days in advance until the due date of notification."
Canadian on the same visa, we applied separately for the visa from Canada. When we extended last year I needed a marriage certificate notarized by my embassy, my wife didn't need her own proof of funds and was considered 'following' me on my visa.