@Iris **********
Sorry, hit enter before I finished! The best part for us Canadians is that we don't need to open and deposit funds to a Thai bank account. As Canadian we can go to the Canadian Consulate in Chiang Mai, or embassy in BKK and get an income verification letter. Then you can take that to the immigration office in Thailand to get your year extension, along with all your other documents.
You can also get them to verify your marriage license/certificate so that one of you can be a "trailing spouse" so you only need to verify the one income.