When you make purchases from the App Store, iTunes Store, or other Apple services in Taiwan, Apple must issue an electronic Government Uniform Invoice and send it to the Ministry of Finance.
When you make a purchase, you will see a dialog that prompts you to provide an email address. Enter the email address that you want to use to receive your eGUI email receipts. You must verify your email using the code that Apple sends to your email address. After you set this up, you won't be asked for an email address again.
You can't provide an email address on Apple TV. If you're asked to provide an email address when you make a purchase on Apple TV, try completing the purchase on an iPhone, iPad, iPod touch, Mac, or PC with current software. If you don't have one of these devices, contact Apple support.
If you want to check which email address the eGUI was delivered to for a purchase, view your purchase history.
Change your eGUI email address
If you want your eGUI receipts to be sent to a different email address, contact Apple support.