Cell phone and service

I am moving to Bangkok in the next month or so and will be living there for a couple years.  I will be traveling around Asia for my work, and will require a good international service.  Am I better off buying a phone in the US, and then getting a service when I get to Thailand, or, waiting until I get there to buy both the phone and the service?
I appreciate any advice I can get.

Hello

In my case I bring my phone from UK and buy a SIM card monthly payment can start from as little as 199 THB + VAT for 100mn. There are many suppliers in thailand and some deals can also be available for limited time, ask directly in the shop.

For example as per today, checking some website, an Iphone 6 with 16GB willl cost you 24,600 THB if you sign for a package on top ( phone only will be 25,500 THB ),  and it will go up to 32,400 THB for 128GB, compare with the price in US but you should get it cheaper as everything imported in Thailand got high taxes, unless you buy local brand.

Good Luck
Kris

Depending on which area you are in Bangkok or surrounding province like Nonthaburi or Thonburi or Pathum Thani etc. The 3G phone signal can be very bad.

Speaking from my personal experience AIS 3G signal is VERY BAD in my area. At times it's 2G or no service thus you can't communicate at all.

All phone companies signal strength is good in shopping centers but when other areas, it's subjective.

So far TRUE is good for 3G in Bangkok and they have better prices compared to other phone companies. But their signal strength drops in other thai cities.

Personally I suggest use 2 companies if communication is crucial for you. Use True and DTac.

AIS has not solved the signal problem for my area since November last year. they had sent me an email which they will take a few months more.

Hi Kris,
Thank you so much for taking the time to reply to my question.  I appreciate your help.
Steve

Thanks for your reply!  I appreciate your help