Calling back to HK is 011-852-xxxxxxxxxx (those xxx is HK phone number.)
This only works with your phone at home in USA, and your home telephone needs to have an International calling plan. If the home telepone did not sign up for an International calling plan, it cannot call to HK.
If you are calling from a public phone or cell phone, you need a calling card.
Here is how you use a calling card:
1. Dial the phone number on your calling card.
2. It will ask you to input passwordL Dial the password from your calling card
3. it will ask you for the number you want to dial... For HK, it is alway 011+852+whatever your number is.