Most immigrations accept an extension only 30 days prior to your 90 days visa expires, some 45 days.

@Dianne *********

Sorry, only if your embassy in Bangkok offers to give you a affidavit letter confirming your monthly income.

As long as you apply in UK with a UK passport you can just upload ID-page of your passport one more time. Also drivers license, utility bill or bank letter with name and address.

@Kool ******

But they don’t accept a affidavit letter from your embassy confirming income as for retirement.

@Ben ******

Not correct, you can apply for a Non O visa inside Thailand too on a TM.86 for tourist visa and TM.87 for visa exemption.

@David *******

The complete and perfect answer.

@Ant **********

Ok, normally it’s 14-21 days on your current stamp and there’s more than 80 immigrations in Thailand. Chiang Mai requires 15 days.

@Jim ******

Only Jomtien/Pattaya Immigration requires two months seasoning also for the initial 90 days visa against formal regulations.

For the first year extension it’s two months seasoning.

@Ant **********

Generally you just need the funds in your account at date shown as an international transfer, unless you apply at Jomtien immigration. For the extension of stay you’ll need two months seasoning.

Depends on the immigration, but they require minimum 14-21 days left on you current stamp to apply for a Non O in country.

If you need more time you should consider to do a border bounce with a professional transport company in order to get another 60 days visa exemption.

Do as Peter says, visit your immigration and get a hand out list of requirements for a Non O in country.