HOW TO install a Thai SIM card in your mobile phone

… and use it in other South East Asian countries too. A quick guide to saving yourself a lot of money and letting you stay in touch with family and friends back home.

Use your iPhone while travelling in Thailand
Use your iPhone while travelling in Thailand

(UPDATE: see also How To Get A Thai SIM Card for your iPhone for step by step instructions on how to get your iPhone and iPad working in Thailand without expensive roaming fees]

Everyone knows that global roaming rates charged by mobile phone companies are extortionate – but everyone wants to stay in touch with home too. What to do? Get a local SIM card when you arrive in Thailand and you’ll be able to send cheap text messages and make reasonably priced calls whenever you want – and you can also use your phone in other South East Asian countries while you’re travelling around. (You can also read the email in your Gmail account on your mobile phone if you have the right model too).

Here’s what to do: Before you leave your home country, check your phone handset isn’t locked – i.e. it will work outside the country. Some manufacturers lock handsets to prevent them being used outside their original market. If you discover your handset is locked, don’t despair – you can pick up basic, low-end Nokia handsets in Thailand for around 2500 baht. Look in MBK Centre or Fortune City IT Mall in Bangkok. I’m very fond of my Sony Ericsson 750i, which is quite an old model now but does everything I need.

Once you’re ready to get your Thai SIM, try this:

1) Go to a Thai phone shop – e.g. Telewiz. Ask for a 1-2-Call Starter Kit. 1-2-Call is the biggest network in Thailand and has probably the best coverage – but all Thai mobile coverage is pretty spotty. They cost around 250 Baht.

2) Take out your existing SIM card and put in the 1-2-Call SIM card. Remember to put your old SIM card somewhere safe!

3) Dial *120 on the phone and press the green Call button. This is required to make your SIM start working.

4) Listen to the automated service and follow the instructions. Press 2 to select English when prompted. It won’t take longer than 30 seconds or so, and will confirm you have 100 Baht credit on your phone to begin with.

5) That’s it! You’re all ready to start using your phone.

To call or text people in other countries, dial 001 + country code + the person’s number, minus the first zero of their number.

For example, if I was calling 01234 567891 in the UK, I would dial 001 44 12345678910

Or you can simply use the + symbol instead of the international dialing code 001. e.g. +441234567891

Texting in Thailand is extremely cheap – around 5 Baht a text. Texting the UK and USA from Thailand is also cheap – around 10 Baht a text. Calls are more expensive, but not outrageous. Certainly a lot cheaper than using a UK or US provider on roaming. You can check your credit balance at any time by dialing *121# and pressing the green Call button. This will tell you your balance. Check your balance before and after an international call to work out how much you’ve spent.

7) You can buy top up cards to add to your phone’s credit from any telephone shop and any 7-11, which are everywhere in Thailand. They come as 300 Baht and 500 Baht credit. In Thai, “saam roi” is 300 and “haa roi” is 500.

8) You can also use your Thai phone in other South East Asian countries. To enable roaming, dial *125. That should switch on roaming automatically.

Some people say on this ThaiVisa forum thread that SMS doesn’t work on 1-2-Call roaming, but I’ve successfully texted from Singapore to Thailand while roaming. However, I could receive texts in Cambodia but not respond to them..

To make calls while roaming, you need to add the prefix *131*

So the format of the number to call is *131* -country code – phone number.

You can call 1-2-Call on 1175 (select 2 for English) and speak to a Customer Service Representative for more information. Verify ahead of time about the ability to call and text from specific countries you are visiting – don’t just assume the global roaming will work when you get there!

If you use roaming in other countries on your 1-2-Call card, be sure to generously top up your credit on your phone before you leave Thailand. I don’t think there’s a way of increasing the credit while you are outside Thailand.

When you arrive in the new country, you will be automatically texted by the local network to tell you that you have coverage. Note that these other telcos seem to take 30 to 50 baht off your phone credit just for the privelige of connecting you before you’ve made any calls or sent any texts, so bear that in mind with your credit. Also remember that because you are roaming, calls will be a lot more expensive than within Thailand.

Previously: Sony Ericsson 750i review: the perfect travel phone?


  1. hi there,

    not sure if you can advise me on this? my 1-2-call sim card expires on 13th jan 2008. i will only arrive in Bangkok on 14th jan 2008. will i still be able to reactivate this card?

  2. 12call sucks
    you loose your number and credit if you not upgrade. 300 baht a month and what if you not use 300 baht you loose. YES. DTac is better the same number for years upgarde or not

  3. You can top up from anywhere in the world, so shouldn’t have to worry about an expiring number. *100*top_up_number# for dtac, *120*top_up_number# for AIS. If you need a top up card while outside of Thailand check out

  4. I just walked in to a 7-11 and asked about a prepaid. The guy there took my phone and did everything (changed the SIM-card, did the necessary settings, etc.) for me. When I walked out, I had fully functioning thai number and could call right away. Easy! I am sure that this won’t happen in every 7-11, but probably in tourist areas it works.

  5. A question about hardware for any switched-on folks out there: will my bog-standard (read: low-end) UK-bought Nokia work in Thailand (with a Thai SIM)? It doesn’t work in the US. Something about GSM vs CDMA networks. Thanks!

  6. Hi Marlies – yes, your GSM Nokia will work fine in Thailand. Have fun!

  7. hi chris,

    what about internet? does thailand have a mobile internet infrastructure?


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