I was talking to a person at a language school about a 1 year ED visa. She said I would need to show a one-year lease. I told her I didn't have that, and then she said okay fine, you could get a six month lease from your landlord.

I don't have that either, and frankly I prefer not to. My landlord has allowed month-to-month leasing. The lady at the school made it sound like I need at least a six month lease.

Is that the exact requirement -- 6 months? Or can I show a three month lease?

The ideal option would be to find some substitute to a lease, if possible. I don't really want one and it would probably create a hassle for my landlord as well.

1. There is no record of any Thai consulate ever having asked for a lease as part of the requirements for a non-ED visa.

2. I doubt very much that the language school can assist you in getting a one-year visa, ie a multiple-entry non-ED visa.

You will not need the agreement to get the single entry non-ed visa that will give you a 90 entry. There is not a one year ED visa unless you get a multiple entry visa that allows 90 day entries for a year.

You can get a total stay of one year by getting 90 day extensions of the 90 day permit to stay you will get from the ED visa.

You will need a rental agreement as proof of residence when you apply for a 90 day extension at immigration. You can use a rental agreement of any length to satisfy immigration.

Yes I'm currently on the 90 day +3 90 day extension ED visa at the moment ( from a different school a year ago). Good to know about the lease not requiring a specific length of stay, I'll keep that in mind thanks.

Landlord can give you open lease contract no end date, many do for foreigners, if you really need one.