Since I travel a lot when working I need a sim card that can be used internationally. Up til now I have used a prepaid DTAC sim card in Thailand and a sim card from my home country when traveling.

I would like to have just one sim card so I went to a DTAC shop today and was told that if I wanted to use a post-paid sim card abroad I had to call DTAC and notify them of where I was traveling and for how long I intended to stay! What the hell???

I asked why this was so but got no answer.

Could someone with a post paid DTAC sim card tell me if it is a big inconvenience for them or not? Is it possible to "open up" the sim card for several countries at a time or just one (I sometime visit several countries in a couple of days when e.g. flying in from South America or Africa)?

Thai Wife has DTAC sim and she also has to inform them where she is going simply so they can actuvate it for overseas use, and they ask approx how long, for security purposes to ensure no one hi-jacks/piggy backs your sim and runs up HUGE bills or burns out whatever pre-paid credit you have which happens quite frequently in Thailand, You may be elsewhere but someone somewhere in Thailand may hack your sim. Wife once had a list of calls to ITALY logged against her and some others to IRAN !........so we know it does happen, once it has you have to dump that sim or they'll be back to spend more of your money.

You should just be able to phone the call center and ask them to enable roaming for wherever you are going. Beware the prices though - especially the data. On a recent trip to Laos they wanted about B 450 per MB.

Have you had a chance to review the terms here?

Seems like they cover everything?

I believe pre-paid IR and post-paid IR are handled quite differently.

You obviously should review the rates, which can be quite high versus using a local SIM.

Both DTAC and AIS have a pretty big collections issue on post-paid IR accounts as people return to a ~ 20,000 + baht bill and then claim the phone/SIM was lost or stolen, and refuse to pay.

I have a post pay DTAC SIM with IR enabled. Yes, call rates are expensive, 100 baht/min or more so I only use it for emergencies. I don't dare touch data. There's a maximum amount of credit that DTAC gives, depending how long your account's been open so a ~20,000+ baht bill is highly unlikely. It's worked throughout Europe and Asia.

I've got a smart phone so I use Skype when ever I can.

Both prepaid and postpaid DTAC have IR services to multiple countries. Need to activate before traveling and renew activation every 6 months (?? check period on their web site). Activation status can be checked online. Only difference between prepaid and postpaid apart from rates is prepaid doesn't allow data services, only voice and sms.

Thai mobile service providers have very low priority roaming deals with service provider overseas. as a result, EXTREMELY high roaming bill to us. sometimes about the price of an air ticket, a 5-digit bill !

alternatively, I used to buy a local pre-paid sim on arrival, that covers voice and data ( may be even wifi ). then I forward my local number to people absolutely necessary, and rest of the communication via texting or instant messaging.

poor traveller !