What documents do I need to extend my Non-O visa for retirement in Thailand?

The main thing you are missing is a Thai bank account with 800,000thb in it. This money needs to be in there for two months before you can apply for your retirement visa.

Hello everyone, I had some follow up questions that go along the lines of what this gentleman is asking.

If I get an OA visa from outside the country, I understand there is no long-term rental requirement for approval. However, once I am approved for the OA and enter the country, when I open a bank account, will they require me to provide a long-term lease agreement in order to open the account, or will the visa I have be enough?

Separately, if I renew my OA at the end of the year, will I be required to simply ‘list’ my current residence at that time, or will I need to show a long-term rental agreement? I want to travel the country for a bit and not sure I want to commit to a long-term rental initially. Was just curious if there was a point when I would have to provide a rental agreement with regard to the OA? Thanks in advance. 

You need a tm30 to show your address and insurance not required.

You are mixing two different visa types. Your link is for the non OA (notice the A).

What you got in your passport is a non O (notice there is no A)

The non O will get you stamped in for 90 days, and can be extended for a year at a time inside Thailand, by meeting the requirements from the immigration office in Thailand. Typically that means having to bank 800K in Thailand to at least get the first year extension. It is possible to use an income affidavit instead if yor embassy provides one. UK, US and Australia (just to mention some) don't provide those anymore. After the first year extension you can change to monthly transfers of 65K if you plan it right.

The non O can be acquired with funds in your own country, if bought at a Thai embassy.

The non OA will get you stamped in for a full year. It is multiple entry, and every time you enter Thailand within the validity of the visa itself, you get stamped in for a year. You can utilize that to get 2 years out of it, by exiting and then re-entering Thailand just before it expires.

However, the non OA requirements include health insurance for example, while the non O does not.

The non OA can only be bought from outside Thailand at an embassy.

The non O can be bought inside and outside Thailand.

Some people choose the OA because they don't then need to bank 800K in Thailand. They can go back home and get a new OA when it's depleted, or extend it in Thailand by also showing 800K banked in Thailand, and the health insurance.

The non O is aimed at you just extending it every year in Thailand. It has no requirement for insurance, but the same monetary requirements as the OA.

Also the MFA have nothing to do with requirements for extending visas within Thailand. They sell visas to enter Thailand.

Visit your local immigration office (Chaengwattana) to ask for their requirements as each office has different requirements.

Are you applying for a "NON-O"? Your link shows a "NON-OA" - two different requirements

That link is about the Non OA visa. It requires health insurance. The Non O and extensions from it don’t.