Your World SIM card is a UK phone number, beginning with the UK country code 44. Regardless of where you are in the world, callers always use the same number to call you. You cannot use your HanaCell US number abroad. If you used your World SIM card in the US, you will be charged at the higher international roaming rates.
You will receive text messages from the networks you connect to around the world. For the most part these messages are simply to welcome you and thank you for connecting to their network. As nice as it is to receive Welcome Messages they are Spam and should be treated as such. It is important to delete any unsolicited text messages and ignore any information they provide. Any customer service numbers or call rate information included within them do not relate to our service. Do not reply to them, or call any of the Customer Service numbers in them, as they can be very expensive.
We recommend that you save your contacts in your cell phone so that you can retrieve them using either your US SIM card or your world SIM card.