Thinking about retirement visa in T'land and esp the $$ aspect.I could dump US$28K in Thai bank account which would cover the need. I might just leave that money sit so could i expect some interest on this money and what might current rates be? Or some have said better to show continuing income from USA SocSec and put as little as possible into Thai bank. And what do i need to show this continuing income stream? Bank statement or govt letter or ??

You'll receive plenty of good answers in the Visas section, moving to the Visas forum.

If you have the cash interest payment is higher here than likely in US - about 3+ percent now for fixed deposit accounts. You use bank statement/passbook and letter of account balance from bank.

If you use income you must obtain letter from Embassy each year of your declared monthly income signed before Consular Officer.

You also have the option to use both with a combined total of 800k baht per year or more.

In addition to comparing the interest rates, you may want to look at the exchange rates. If you look at the chart below, back when the dollar (or Euro or pound or whatever) was not buying as many baht, the whining on Thai Visa was so loud that satellite TV reception was being effected and many of those gnashing their teeth were planning on leaving because of the reduced amount they were getting each month.

At the moment the rate is more favorable than it's been for awhile. There's no guarantee you'll win at trying to time the rates, but usually if you buy baht at the upper end of the range and then live off that money when the exchange rate sucks, you'll find that more profitable than worrying about the interest rate differential.

Of course, there's no certainty about that benefit going forward, but it's worth considering. Most of the time I've been here I've been fairly lucky using that approach.

Purely up to your if you use the Bt800K in a Thai bank, a home country Embassy letter showing the required income, or a combination of the two. I did the Embassy letter route for the first few years over here and didn't keep much money in Thai banks...I would just use ACH/wire money over as needed and/or use my no foreign transaction fee US debit cards to get money. But several years ago I got tired of paying the embassy $50/Bt1600 for an income letter and making the trek to the embassy to get the letter...the trek was really not hard for me since I live in Bangkok but if you don't live in Bangkok then it can become a trek unless the embassy happens to be making a visit to your area just before your extension is due.

So I switched to keeping Bt800K in a "fixed" saving account with a Thai bank, specifically Bangkok Bank. By fixed I mean you need to leave the money in the account for X-months to earn the full interest...you can pull part or all of it out whenever you want, but you lose the bulk of the interest earned by pulling the money before the account matures after X-months. Depending on the period of the fixed account (i.e., 3 months, 5 months, 12 months, whatever amount of months) just use a 3% interest earned for planning purposes...sure beats the regular savings account which is down around 0.5 to 0.75% interest earned. You would want to get one of these regular savings accounts also for you day-to-day spending money, debit card, ibanking, etc.

This fixed savings account also serves as my emergency funds/need big money NOW vehicle. Now, on fixed accounts 15% of the interest earned is withheld/sent to the govt; but this money is easily refunded in Jan-Mar of each year by filing a simple form with your local tax revenue office...you are not doing a Thai tax return...just filing a form to get the 15% withholding tax on the interest refunded to you....take 2 to 6 weeks depending on how speedy your local tax office is.

So, each year when it's time to apply for my yearly retirement extension at Bangkok Immigration I show up at the Bangkok Bank branch in the govt building that immigration is in also, pay Bt100 to get the bank letter confirming I have Bt800K in the bank, attach copies of my passbook to the bank letter to prove the seasoning period has been met (2 months on first extension; 3 months on subsequent extensions) and go upstairs in the govt building to apply/get my annual extension of retirement.

Yeap, I much prefer the Bt100 for a bank letter I get in 5-10 minutes compared to around Bt1600 for the embassy letter which includes a trek to the embassy after I got the appointment. Also, you will read in some post that some immigration offices will basically ask you to show proof of income to support the embassy letter....they won't do that with a bank letter that shows you have the Bt800K in the Thai bank--nothing to challenge...the money is definitely there. Now if you do the combo method of say X-amount in the Thai bank along with a embassy letter which effectively adds up to meeting the Bt800K in bank/Bt65K per month requirement, they I've read some posts that some immigration offices apparently wanted additional proof the funds were coming "into" Thailand on a regular basis...but these posts seem to be the exception.