How long does it take to obtain a marriage visa in Thailand and are there extension options during the application process?

Forget the Tourist visa and get the Non Imm O in your home Country. Makes the process much easier

Why not get the Non-O marriage visa from your home country to get 90 days on arrival and make the task of getting a Thai bank account easier (assuming that you are already married)

I might add to what Brandon has mentioned already. When you go to immigration with anything concerning a marriage visa/extension always take your wife with you, or they won't talk to you. They will tell her in Thai things that are not on the list they give you that are local office specific. Always take your wife with you.

Marriage visa and extension is a multi step process.

First, you go to your immigration office and ask for their handout for conversion to non-O visa. Then you gather all the documents and make sure you have the 400,000 baht in the bank.

Next you apply for the visa conversion when you have at least 14-21 days left on your stay, depending on the immigration office.

You will receive an "under consideration" stamp of 14-21 days and will return at the end of this stamp to get your new visa. The immigration officers may want to do a home visit during this time. When you go, ask for their list of requirements for a marriage visa extension.

Then you wait until you have 30 days or less left on this visa stamp (approximately 60 days) you gather all the documents from the second list you received and you go to immigration and apply.

Again you'll receive an under consideration stamp, usually 30 days but varies by office. Again they may want to do a home visit, interview your neighbors, etc.

After this consideration period ends you go and receive your 1 year extension.

You can then spend the 400,000 and just make sure it's back in the bank 2 months before you'll apply for the next year's extension (not 2 months before it expires, 2 months before you apply)