Sim card from Zhuhai

Annie, you really worry too much. If you stay in Zhuhai and Macau, you should buy two sim cards, one in Zhuhai and the other in Macau. If you just buy one, you need to pay expensive international roaming fee. And you need to buy the sim card according to your phone mode. If your phone supports WCDMA, then you should by China Unicom's sim card in Zhuhai. In Macau, as long as you don't buy China Unicom's sim card, you can buy any other type that supports WCDMA.

If you buy one in Zhuhai, then you need to show your passport and pay the deposit. The expense actually depends on what package you choose. In Macau, you can buy prepaid cards. There are many types and you just buy one according to your needs.

As for the public phone at the airport, you shouldn't worry. If you don't use up the coins, they will automatically go out after your call is made. Please add 0086 before you make the call to Zhuhai. If it is a fixed phone number, you need to add the areal code 756 after 0086.