What is the best way to apply for a retirement visa in Thailand while currently on a tourist visa?

Agents are money grabbers

It's not difficult to apply for a retirement visa whether u are in UK or thailand if have the required funds but the difficult part is to open a bank acct in thailand without a long term visa as u will need a thai bank acct for future extensions....hence most ppl suggested that u get the 90days nonO in your home country with funds at home bank den u travel to thailand with the nonO and get a thai bank acct with that as u will need to transfer your funds to thai acct for future extensions in thailand things will be easy if u use a agent but are u going to pay the agent every time u do a extension? Many ppl have also done it themselves without the agent it's about learning the process and once u got it right u just do the same every year immigration offices have handouts of what is needed to do the extensions

Tom..when you make your move into Thailand I recommend you use an agent to help you. You will have to pay but I found it very helpful

I do so it was so easy to get marriage visa here

It is straightforward and easy to get just make sure you have a genuine resident situation and is easy if you're lucky enough to have a thai wife you only need 400k in the bank

Apply for 90 day non o visa in home country when you get here go to immigration and get a residency certificate and ask for a letter for the bank to open the account

Definitely 90 day Non O

If you're already planning to return to the UK, then it's 1000 times better to apply for the 90 day non-O visa while you're there. Not only will it let you open a bank account in Thailand, it will also save you at least 2 trips to the immigration office, which in some cases can be an all day affair. Instead you just submit a few documents online from your computer to the Thai e-visa system and wait.