What are the financial requirements for a marriage visa in Thailand compared to retirement options?

Your best bet is to put the 0 in a separate bank account for the immigration and just forget about it and use it every year to show them. Make sure that your account is easily accessible to keep the immigration happy

As i guess your from UK, you have to use the banked method for your visa application and first 1 year extension, but even before you get your first extension start banking the monthly amount. You have to maintain the initial banking deposit for 3 months, but you can spend the monthly ones. That way you fulfil the first extension requirements of 5 months deposit , and the second extension can be done on 12 monthly deposits by time of application. Obviously as Jan said easier if you have been working here.

Formally it’s 40 K baht a month, but unless you earn the money in Thailand monthly transfers might work and it might not. More and more offices are saying if you don't legally work in thailand and make the minimum 40K baht a month salary to meet the monthly income requirements based on marriage extension you cannot use monthly incoming transfers from overseas of 40K baht a month for the previous 12 months. It's just a crap shoot on whether your immigration office will or won't allow it, and they wouldn't allow it on the first yearly extension off a 90 day Non-O because you wouldn't have a year's worth of 40K baht a month transfers <- meaning you either legally work here with a work permit and the appropriate minimum salary, your embassy still issues the income affidavit OR you bank the funds.

40 k a month