I've loaded 300 baht on to a new TrueInter Sim and its pushed the validity forward by one year which is excellent.

If I now add another 100 baht for example when the 300 starts to run low will it push validity further forward by a month or more ??

For 1 baht a minute to landlines in Europe USA and Canada its excellent.

10. Participants of this sales promotion will get 365 days service validity immediately by topping up value from 10 baht to 1,000 baht. The subscriber can only collect service validity up to 365 days.

http://www.truemove.com/en/Inter-SIM-Prepay-condition-1.rails

rates: http://www.truemove.com/en/product-pre-new-sim-intersim-pop1.html

10. Participants of this sales promotion will get 365 days service validity immediately by topping up value from 10 baht to 1,000 baht. The subscriber can only collect service validity up to 365 days.

http://www.truemove.com/en/Inter-SIM-Prepay-condition-1.rails

rates: http://www.truemove.com/en/product-pre-new-sim-intersim-pop1.html

Am guessing but by reading the link any further credit added will just push validity date forward to 365 days each time ??

Was unaware that this 1 baht a minute was a promotion and it appears it will revert to another rate at the end of September ??

10. Participants of this sales promotion will get 365 days service validity immediately by topping up value from 10 baht to 1,000 baht. The subscriber can only collect service validity up to 365 days.

http://www.truemove.com/en/Inter-SIM-Prepay-condition-1.rails

rates: http://www.truemove.com/en/product-pre-new-sim-intersim-pop1.html

Am guessing but by reading the link any further credit added will just push validity date forward to 365 days each time ??

Was unaware that this 1 baht a minute was a promotion and it appears it will revert to another rate at the end of September ??

The T's and C's seem straightforward to me, any top up from 10 baht to 1,000 baht extends the expiration date to 365 days. Not sure what's confusing about that? If you have 1 day left and top up with 10 baht you will have 365 days; if you have 364 days and top-up with 1,000 baht you will have 365 days. You cannot have more than 365 days.

The promotion date has been extended a number of times over the past few years. Obviously they can change the rates at any time without notice, and these terms are just standard boilerplate for protection, but I might expect they'd extend the current rates for another period, unless they actually want to return to profitability at some point.

Also note the "90-day activity" requirement:

11. Subscribers who do not make call or top up TrueMove Prepay credit within 90 days, True Move has the right to temporarily suspend the service for 18 days and service will be automatically terminated on day 19th.

What I did try was using the 1 baht access rate, and then the 3 baht "premuim" rate.

No difference whatsoever-nothing.