If you're travelling to Asia, one of the easiest to use and affordable SIM cards is the AIS SIM2FLY.  This will also probably replace my FreedomPop SIM Card since it doesn't really seem to work anymore nor does it work in Asia

Purchase Link: https://simcartonline.com/en_intl/ais-sim2fly-4g-8-days-data-prepaid-sim

The hardest part of using the SIM is if you need to extend the data period.  Below is how I topped up and added additional data to the SIM card.  Note: the FLY! FLY HIGH !! was very helpful in the below instructions.

To use the SIM, just stick it in your phone when you land in the destination country. This is important. The SIM is active the first time you use it, so don't stick it in until you land!

  1. To top up, download the LINE App.
  2. Download the My AIS App:
  3. The instructions below are for Android, but should be similar on iOS Registering a credit card with LINE Pay:
    a. Open the LINE App, and press "More"
    b. LINE services
    c. LINE Pay
    d. Add Card
    e. Verify your identity[1]: https://help.line.me/line/?contentId=20000655&country=JP
  4. When you LAND in your destination country, open up the My AIS app and follow the on screen instructions to register. Registering requires receiving an SMS on the SIM.[2]
  5. Topping up:
    a. Press Top Up
    AIS1
    b. Press Top Up
    AIS2
    c. Confirm your phone number, choose Rabbit LINE Pay[3]. I was only able to top up 40bhat before I verfied my account
    AIS3
    d. Confirm the amount
    AIS4
    e. Get redirected to LINE Pay app
    AIS5
    f. Confirm your payment with LINE Pay
    AIS6
    g. Pay[4]
    AIS7
    h. Complete
    AIS8

Use the SMS Short Codes to add your desired package[5]:

SMS Code Cost / Information
*111*358# THB 849 - 4GB 15 days including Western countries
*111*359# THB299 - 1GB 3 days including the US and Europe
*111*354# THB 299 - 4GB 8 days Asia / Australia
*111*356# THB 119 - 1GB 2 days Asia / Australia
*111*600# THB 2,699 - 15GB 1 year Asia / Australia
*111*407# THB 99 - 2GB 7 days Cambodia, Laos, Malaysia, Myanmar
*111*350# THB 246 - 100 MB 30 days correspondence countries
*120* (Top Up code) # refill card use was TopUp
*121# prepaid balance and expiration date confirmation
*121*3# apply in Thailand for the Internet pack confirmation
*121*32# remaining in Thailand for the Internet pack Capacity · Due date confirmation
*111*6# SIM 2 Fly Roaming Plan currently in use · Remaining capacity · Check deadline
*545# Display phone number

  1. If you don't verify your identity, LINE Pay may stop your account until you do and you won't be able to top up. I ran into this problem, but luckily had topped up enough to finish the trip. My LINE Pay account is now verified. ↩︎

  2. It may be worth trying press the "Create my AIS" button. This should allow you to associate an e-mail address and link multiple phone numbers to one account. I did not do this and will try the next time I use the SIM. ↩︎

  3. Only Thailand Credit Cards work for the Credit Card section ↩︎

  4. Home Trust Visa only allows 15 transactions per day, local time of the card. So becareful how many times you top up and whether you need to use the card for other purchases ↩︎

  5. Borrowed and formatted from: http://flyflyhigh.net/archives/50097131.html ↩︎

References:
Top up: http://flyflyhigh.net/archives/50067613.html
Alternate Top Up: https://mobiletopup.com/