Your roadmap should be:

1. Apply for the single entry 90-days Non-Immigrant O retirement visa in your home country or in any of Thailand's neighbouring countries, before you travel to Thailand.

Prove either that you got the equivalent of 800.000 THB in your home bank account (or in your Thai bank account)

or

that you earn a minimum of equivalent of 65,000 THB per month. For the application to the initial visa in your home country, you can use original income documents.

2. enter Thailand and get stamped in for a 90-days stay permit. The visa itself will expire and become invalid for further use.

3. Visit your local Immigration Office for a Certificate of Residence and the hand out list of requirements to apply for the 1-year Extension of the Stay Permit

4. Visit a bank branch with passport and COR and open a bank account. Transfer a minimum of 800.000 THB to your account. If the banks won’t do it, pay an agent around 5000 THB to open an account for you

You could use the “income method” however that means you need an “affidavit of income” legalized by your embassy in Bangkok as proof of income on Immigration

Some country’s embassies do not issue them any more leaving you with the only option of using the 800K deposit method – at least in the first year.

These countries are AFAIK the USA, UK, AUS, Norway and Canada

5. Wait 60 days and prepare the documents mentioned on the hand out list.

6. As soon as the 800.000 THB have seasoned for 2 months, get the bank statement, visit Immigration and apply for the 1-year Extension of the Stay Permit based on Retirement

You can theoretically do everything by yourself, no agent needed, but it takes certain pressure out of the process if you let an agent handle some parts of the applications

Your wording is wrong.

„I arrived in Thailand on a non o 90:dy visa from uk with intention of getting a retirement visa”

It actually is totally different:

*** you arrived in Thailand on a 90-days Non-Imm-O “retirement visa” and got stamped in for a 90-days stay permit

The visa itself becomes invalid upon entry

***you have the intention of getting a “1-year extension of the stay permit” based on retirement.

on a 90-days Non-Imm-O family visa, you can fly one-way. You don't need an onward-travel proof. If the Check-in does not comply, ask for the manager and explain to them that this visa is the first step for a longstay in Thailand

@Mike *******

must add: "I think they will also accept an income proof of minimum 40,000 THB monthly, but you will need an income affidavit from your embassy. Not every embassy is issuing the affidavit."

should be like this, but it can be a bit different from one Immigration to the other. Best is you visit them and ask for the handout list of requirements

@Patty ******

in the first two years you can squeeze from a Non-Imm-O/A visa, Immigration will accept an overseas insurance (as long as they sign the F.I.C.). However when you move from the visa to the "12-months Extension of Stay Permit" beginning from the third year, Immigration only accepts a tgia-listed Thai private health insurance

never go into an overstay knowingly! Avoid it !

change your home branch. Get your TM30, visit Immigration and ask them for the certificate of residency. Then visit the bank branch and ask them to update your address and phone number. Done

@Bob *********

he is 19

yes, every U.S. Dollar has double the purchase power in Thailand. You pay less than half for rentals, local food, electricity, water, carwash and restaurants, just to name a few.