you might need this account, because since recently, some Immigration offices have started to require a few transfers from abroad from applicants who use the embassy income affidavit. You need to ask your Immigration office what their current policy is
some Immigrations have changed their policies against applicants who use the income affidavits of their embassies. They now additionally require that the applicant has a Thai bank account, and can show a few transfers having come into it from abroad . . . . . The OP should URGENTLY ask "his" Immigration if they require a Thai bank account, additional to the embassy affidavit
not even in this case would a tourist visa whitewash the fact that you used "touristic entries" for a longstay in Thailand. It doesn't make any difference - both the visa-exemptions and tourist visas get scrutinized if used "too many times" in a row
the exchange rate of today doesn't match these numbers, so I would only touch it with a pair of golden tweezers. He can however do the math himself on how many GBP will equal the minimum of 800,000 THb in today's exchange rate
the 90-days Non-Imm-O retirement visa is valid for use for a single entry within three months counted from the date of issue. This will be noted on the .pdf visa document under "visa must be used by" and the date
when entering Thailand on a Non-Imm-O Retirement visa, you will get stamped in for a 90-days stay permit. The visa itself will become void and invalid for further use. You should immediately get a Thai bank account opened and transfer the required 800,000+ THB. You can then apply for a 1-year Extension of the Stay Permit based on being over50/retired on Immigration as soon as your minimum of 800,000 THB have been sitting in your Thai bank account for 2 months - and you bring to Immigration the "bank letter of guarantee" which certifies this on the day you apply
when you apply for the Non-O Retirement Visa in the UK, you EITHER need the equivalent of 800,000 THB in your UK bank account, OR show proof of a monthly income of a minimum of the equivalent of 65,000 THB using original documents. . . . . . . . .however for the application to the 1-year Extension of the Stay Permit based on Retirement, your need 800,000 Thai Baht in a Thai bank account in your sole name since 2 months on the day of application, because you cannot use your income proof on the Thai Immigration (your embassy doesn't issue certified income affidavits)
well, and you are already on the "1-year Extension of Stay based on Retirement", then this 90-days Non-Immigrant visa from Chiang Mai in your passport is already invalid. I do not think that Immigration in Pattaya is going to transfer the 90-days visa stamp to your new passport, they normally only transfer valid stamps, which would be the extension stamp