I have an old SIM card I'd like to use. I last used it about 3 months ago and spent all the credit on it. Is there an easy way to know if the SIM (and phone number) is still valid? Will it be obvious once I put the card in the phone?

BTW, I'm not in Thailand now, otherwise I would simply try it.

Thanks,

Dave.

try it! If its AIS - roams most places in the world. (validity depends on how much dosh you put on it - mine is currently 1yr)