There use to be a requirement to provide your identity when buying a SIM - there may well still be. This came about as a result of remotely triggered (motorbike) bombs using mobile phones, predominantly in the troubled three southern most states of Thailand. It may have also had something to do with the then prime minister - Thaksin Shinawatra - having a big interest in AIS, one of the main Thai mobile operators. Collecting more information about your users is useful in many ways...
Also is seems that DTAC, prepaid is called Happy, is the most foreigner friendly of the Thai mobile operators. They even have a slogan "You don't have to be Thai", which is most unusual for a company in Thailand. I guess it shows that DTAC is not really a Thai company. If you want to you can get a post paid SIM with DTAC, which you can keep alive by making online top-ups with your credit card. They have had some very good promotions. I use to be on a promotion Zero, which cost nothing - I only paid for what I used. Now that stopped I moved onto a special promotion which is costing me about 50 baht a month.
A benefot for all DTAC customers is having an online account. With this you can send 50 sms to other DTAC / Happy users per month free. Some where on the DTAC/Happy website there is a short code you can type in to find out if a particular no is on the DTAC/Happy network - you can even find out if the user is in a particular region ! And this works when you are roaming too.
Registration for roaming with Happy was/is free and can be enabled from your online account. I'm not sure now for postpaid. I had to pay quite a bit to have it enabled 4 years ago - still it has been worth it.
For pre-paid longevity it is best to get a Happy "Simple" promotion SIM. With these any top-up will extend the life for 1 year. Currently this promotion is on till the end of march 2010. This has been around for 3+ years and they have been extending the life of the promotion every 6 or so months. The "Simple" promotion doesnt give the cheapest calls, but you can change promotions. For the 1 year longevity combined with cheaper calls there is a promotion for North Eastern (Isaan) people. If your in Isaan or if you have some evidence of an address in Isaan then you may be able to get one of these. You may be able to get one anyway. Like a lot of things in Thailand, if you keep on trying you will get it eventually !
There is also a way of buying extended life for your SIM. Its not a lot - something like 12 baht for 3 months or 24 for 6 months. It is possible to buy extra time for up to 1 year. This is good if you want to keep your sim alive but your out of Thailand.
With a post paid sim and the online account, it is possible to transfer credit to a pre-paid user. I havent done this yet, but I guess it would count as a typical top-up and would extend the life of the sim accordingly.
The DTAC / Happy call centre have good english speakers during the Thai working day. Out of thai working hours it is not so good. The main DTAC customer service centres in Bangkok are very nice and very helpful. English is well spoken there.
My advice would be to not buy a SIM as soon as you enter Thailand as you will not get the real / best price. Check the websites first to know what you want and go to one of the companies actual customer service places and buy there. You will get the actual price and have the best possible selection.
Occasionally, you may find some very good deals on the street. Often these are people who just have a bag and no or a very little stall. You will be able to tell the offer is good as there will be many thai people all around and it will look somewhat unusual. I've had a few deals like this. Typically they are sims that have already been activated, as they were close to their expiry date. I beleive that any of the traders that buy sims may not be able to return them to the mobile co for a refund, so have to sell them to get something back.
Be wary in the big mobile phone malls, like MBK (Mah Boon Khrong) and Pantip Plaza. Don't buy from the first trader you see. Go ask a few then make your mind up. Cheating foreigners (and locals) is an accepted and often used practice.
I've got some links to the DTAC/Happy sites I can post if your interested...
I haven't used AIS or TOT. I have used DTAC/Happy, 3 and True Move. When I used 3 they only had a CDMA network and I'm not sure if they had a roaming agreement with the GSM network. Anyway, the Moto CDMA phone I had was ok, but often didn't have a strong signal. However, this was 4 years ago, so things may well have changed since then.
Also, most of the Thai banks will now allow you to top-up mobile phones now through their online services.
Hope that all helps.
Just dug a few things out that may be of interest :
DTAC Happy Shortcodes - works when roaming
Find out which promotion on
*103*9#
Check no is on DTAC network
*102*<10 digits tel no>#
Check if no is in Isaan region
*102*1*<10 digits tel no>#
Also the Simple promotion can be found at :
::Happy - *1003 Promotion Center::
Happy price plans
::Happy - *1003 Promotion Center::
Also just checked the page for getting a post paid account :
dtac - feel goood
Seems they're not using the slogan "You dont have to be Thai" any more - no surprise there. I'm surprised it actually got used in the first place ! This explains what you need to get a post paid account and what to bring. It doesn't state any requirement to have a Non-Immigrant Visa (a visa that allows you to stay for up to 90 days at a time and with a multiple entry visa may be used to stay in Thailand for up to 15 months). But if you do want a long stay visa, the Thai Embassies and Consulates are now providing Single Entry tourist visas free of charge I beleive. For the latest visa info and lots of other stuff see :
Thaivisa.com - Home or
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