What are the steps to obtain a multi-entry Non-O visa for Thailand from Canada?

you are almost 100% totally INCORRECT there

@David ********

, MOST all the Non-Immigrant Type visas sold at the thai consulates around the world are sold as either single entry OR multiple entry <-(although with this covid shit show going on a multi-entry visa [where you bounce out and back to get a new entry stamp] is not all that valuable.

You are confusing a VISA <- a sticker you buy from a thai consulate before you come here with an EXTENSION OF STAY <-a stamp you get from the immigration office once you're here. IF you get a yearly extension of stay and you want to exit/re-enter you BUY a re-entry permit (single re-entry 1000baht, multiple re-entry 3800baht)

@David ********

there are literally 10,000 or more people in the country that were on a multiple entry Non O visas based on marriage. It was valid for a year and if bought in somewhere like Laos meant no financial requirements, but you had to leave Thailand every 90 days. Pre Covid not a problem. Border bounce same day and you’re back in for another 90 days. Rinse and repeat. Covid killed that option so most are now on a Covid extension for as long as they keep selling those.

@David ********

sorry but you’re wrong. Take for example one that they still are selling - a non OA visa. It’s valid for a year and each time you enter Thailand you’re stamped in for a year. You can come and go as many times as you you like. Each time you get another year stamp. Prior to Covid many used this visa as a two year visa because as long as you left Thailand just before it expired and came back in you got another year - albeit the second year wasn’t multiple entry unless you bought a re-entry permit.

@Stuart ********

Yep. They're not much use at the moment but could be useful info for the OP at a later date.

@George ************

15 days left is for a Non Imm visa, you can apply for the extention of stay right up untill your current admitted to stay stamp expires.

CORRECTION:

As Steve Greir points out below you can do the extension of stay application from 30-45 days before the day your permission to stay expires up to the day it expires.

ORIGINAL COMMENT (requirements below only hold for the application for a Non-O visa inside Thailand):

@M ****

Do it as early as you can, some offices require you have at least 15 days remaining on permission to stay (others 20 days).

Always do things early. Problems can often be solved with time. Without time things become a problem. ;-)